JP3353980B2 - Stereolithography method and stereolithography device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical shaping method and an optical shaping apparatus, and more particularly, to a method of forming a material layer made of a photocurable material, laminating the material layer, and selectively exposing the material to cure. The present invention relates to a stereolithography method and a stereolithography apparatus for forming a three-dimensional three-dimensional object.

[0002]

2. Description of the Related Art In recent years, an optical molding method for forming a three-dimensional object (three-dimensional object) by applying a plate making technique has been proposed. In this stereolithography method, a resin (photocurable material) that is cured by irradiation with light is selectively exposed and cured, and the cured layer is laminated to form a three-dimensional object (a molded object). ing.

[0003] An optical shaping apparatus of this type is described, for example, in Japanese Patent Publication No. 2-48422. This stereolithography apparatus moves a base vertically in a container containing a photocurable resin, and disperses the photocurable resin corresponding to a layer thickness flowing on the base or a cured layer laminated on the base to the atmosphere side. In this case, a three-dimensional object is formed by laminating cured layers by a so-called free liquid surface method of selectively exposing the solid object to a solid object.

Further, Japanese Patent Publication No. 5-23588 discloses that
A base is moved in a direction close to or away from the light-transmitting window in a container having a light-transmitting window and containing the photocurable resin, and light between the light-transmitting window and the base or a cured layer laminated on the base is moved. A three-dimensional object is formed by laminating cured layers by a so-called regulated liquid level method in which a curable resin is selectively exposed through a light transmitting window.

[0005] In this stereolithography apparatus, both the photocurable resin in the container is caused to flow by moving the base and the photocurable resin is exposed to form a three-dimensional object. An expensive light source that precisely controls the curing depth of the curable resin, cleaning after molding, and post-curing treatment (so-called,
Post-curing) is required, and the operation efficiency is low due to the batch processing, and the cost of producing a three-dimensional model is relatively high. In addition, a material having an extremely high viscosity cannot be used, and there is a method of mixing hard particles or the like in order to prevent deformation due to curing shrinkage of the resin, but there is a problem that the method cannot be applied. Further, in the latter optical shaping apparatus, since the hardened layer is in close contact with the light-transmitting window, there is a problem that the hardened layer is deformed or damaged when the hardened layer is peeled off.

In order to solve these problems, the applicant of the present invention has disclosed in Japanese Patent Application No. 5-256205 a method in which a material layer having a predetermined thickness made of a paste-like photocurable material is formed on a transparent sheet belt. After sandwiching the material layer between the transparent sheet belt and the molding base or the lower cured layer supported by this to form a cured layer of a predetermined shape by exposing through the transparent sheet belt, it was supported by the molding base. There has been proposed an optical shaping apparatus for forming a three-dimensional object by sequentially laminating cured layers by peeling an uncured portion of a transparent sheet belt and a material layer from the cured layer.

[0007]

However, in the optical shaping apparatus proposed by the present applicant, an exposure method for selectively exposing a material layer formed on a transparent sheet belt to form a cured layer having a predetermined shape is disclosed. As a means, an image projection device that forms an image of light shaped by a mask on a material layer at an exposure position by an optical system or a laser unit that scans with an ultraviolet laser beam is used. In order to expose the material layer by indirect projection away from the camera, it is necessary to control the projection position with high precision, and the laser unit is expensive due to the expensive laser light oscillation device and control system. there were.

[0008] In view of the above, according to the first aspect of the present invention, the light to be irradiated is shaped by a mask which is in close contact with the surface of the transparent seat belt, so that the accuracy of the light irradiation position becomes unnecessary, and a highly accurate three-dimensional object can be formed. It is an object of the present invention to provide a stereolithography method for molding at low cost. Further, according to the second aspect of the present invention, the light to be irradiated is shaped by a mask which is in close contact with the surface of the transparent seat belt, so that the accuracy of the light irradiation position is not required and the three-dimensional object can be formed with high precision. It is an object of the present invention to provide a stereolithography device.

According to a third aspect of the present invention, a mask is formed on the surface of a transparent seat belt together with a mask to serve as a reference for the position of the mask, thereby facilitating the alignment between the lower hardened layer and the position of the mask. It is an object of the present invention to provide an inexpensive stereolithography apparatus for modeling a three-dimensional object with improved accuracy. According to the fourth aspect of the present invention, by applying a predetermined tension to the transparent sheet belt at the mask forming position and forming the mask without synchronizing with other processes, it is possible to form a highly accurate mask and reduce the time of the process. Accordingly, an object of the present invention is to provide an optical molding apparatus for molding a three-dimensional object with improved molding accuracy at low cost.

According to a fifth aspect of the present invention, the light irradiated on the transparent seat belt is reduced by a predetermined amount to reduce the area of the mask, so that the consumption of the mask material is reduced, and the running cost is reduced. It is an object of the present invention to provide a stereolithography device capable of operating for a time.

[0011]

In order to achieve the above object, according to the present invention, an uncured material layer made of a photocurable material is exposed to form a cured layer, and the cured layers are sequentially laminated. In the stereolithography method of forming a three-dimensional object by
A first step of forming a mask for shaping light into a predetermined shape on the front surface of the transparent sheet belt, and forming a material layer having a predetermined thickness of a paste-like photocurable material on the back surface side of the transparent sheet belt with respect to the mask; A second step of forming, a third step of positioning the material layer in the layer thickness direction by sandwiching the material layer between the transparent seat belt and the shaping base or the lower cured layer supported by the shaping base, and from the mask side A fourth step of exposing the material layer by irradiating the positioned material layer with the shaped light by irradiating light through a transparent sheet belt and forming a cured layer having a predetermined shape, and curing by the exposure And a fifth step of peeling off the uncured portion of the transparent sheet belt and the material layer from the cured layer supported by the modeling base.

According to a second aspect of the present invention, an uncured material layer made of a photocurable material is exposed to form a cured layer, and the cured layers are sequentially laminated to form a three-dimensional object. In the apparatus, a mask forming means for forming a mask for shaping light to be transmitted through shading into a predetermined shape on the front surface of the transparent sheet belt, and a paste-like photocurable material extending on the back side of the transparent sheet belt with respect to the mask. A material layer forming means for forming a material layer having a predetermined thickness, and a molding base for positioning the material layer in the layer thickness direction with the material layer or a cured layer below it sandwiched between the transparent sheet belt, Exposure means for irradiating light from the mask side and shaping light onto the positioned material layer through a transparent sheet belt to expose the material layer to form a cured layer of a predetermined shape, and Move to direction Transport means for transporting the material layer to a material layer forming position and an exposure position, and a belt peeling means for peeling an uncured portion of the transparent sheet belt and the material layer from the cured layer supported by the exposure and cured by the molding base And characterized in that:

According to a third aspect of the present invention, the mask forming means is configured to form at least one or more reference marks in the vicinity of the mask, the mark detecting means for detecting the reference marks, and the molding base being mounted thereon. An elevator that moves the modeling base close to or away from the surface of the transparent seat belt and moves the modeling base in parallel with the surface, and based on information detected by the mark detection unit, stops driving of the transport unit and the elevator to stop the mask and It is characterized by positioning a modeling base.

According to a fourth aspect of the present invention, there is provided a moving roller which applies a predetermined tension to the transparent sheet belt and moves up and down in accordance with the movement of the transparent sheet belt on the upstream and downstream sides of the mask forming means; Roller detecting means for detecting the moving roller moved to the position, and controlling the driving and stopping of the supply bobbin for feeding an unused transparent sheet belt and the mask forming means based on the detection information by the roller detecting means. It is characterized by the following.

According to a fifth aspect of the present invention, the image forming apparatus moves between the transparent sheet belt located at the exposure position and the exposure means,
A shutter is provided to make the opening area of the transparent sheet belt facing the exposure means a predetermined area, and the shutter narrows light emitted from the exposure means to the transparent sheet belt.

[0016]

According to the first aspect of the present invention, in the first step, a mask for shaping light into a predetermined shape is formed on the surface of the transparent sheet belt, and in the second step, a paste is formed on the back side of the mask of the transparent sheet belt. A material layer having a predetermined thickness made of the photocurable material is formed. Next, in a third step, after the material layer is sandwiched between the transparent seat belt and the molding base or the lower cured layer supported by the molding base and positioned in the layer thickness direction, in the fourth step, Light irradiated from the mask side and shaped by the mask is applied to the material layer via a transparent sheet belt, and the material layer is selectively exposed to form a cured layer having a predetermined shape. Next, in a fifth step, the transparent sheet belt is separated from the cured layer supported by the molding base by being cured by exposure. At this time, the uncured portion of the material layer on the surface of the transparent seat belt is also separated (separated) from the cured layer. And
These first to fifth steps are repeated, and the cured layers are sequentially laminated to form a three-dimensional object.

According to the second aspect of the invention, a mask for shaping the irradiated light into a predetermined shape is formed on the surface of the transparent sheet belt by the mask forming means, and a paste-like mask is formed on the back side of the mask of the transparent sheet belt. The photocurable material is extended by the material layer forming means to form a material layer having a predetermined thickness, and the material layer is moved from the material layer forming position to the exposure position by moving the transparent sheet belt in the predetermined direction by the conveying means. Conveyed. The material layer positioned at the exposure position is sandwiched between the transparent base belt and the lower hardened layer supported by the molding base or the molding base in the previous molding, and is positioned in the layer thickness direction. Light is applied from the mask side by the means and shaped by the mask is applied to the material layer via a transparent sheet belt, and the material layer is selectively exposed to form a cured layer having a predetermined shape. Thereafter, the transparent sheet belt is cured by exposure and is separated from the cured layer supported by the modeling base by a belt separating unit. At this time, the uncured portion of the material layer on the surface of the transparent seat belt is also separated (separated) from the cured layer. The operation of each means is repeated, and the cured layers are sequentially laminated to form a three-dimensional object.

According to the third aspect of the present invention, at least one or more reference marks are formed on the mask and the vicinity thereof by the mask forming means, and when the material layer is transferred from the material layer forming position to the exposure position, the mark detecting means detects the mark. The reference mark is detected, the movement of the transparent sheet belt by the conveying means is stopped, and the mask is positioned. Then, when the molding base is moved in parallel to the transparent seat belt surface (in the width direction of the transparent seat belt) by the elevator and the reference mark is detected by the mark detecting means, the movement of the molding base by the elevator is stopped and the molding base is stopped. Is positioned.

According to the fourth aspect of the present invention, when the upstream or downstream side of the transparent sheet belt is shortened by the formation of the mask by the mask forming means or the movement of the transparent sheet belt by the transport means, the transparent sheet belt is raised and moved to the upper limit position. The moving roller is detected by the roller detecting means, and the supply bobbin or the mask forming means is driven to send out the transparent sheet belt. Then, the moving roller which has been moved down to the lower limit position is detected by the roller detecting means, and the driving of the supply bobbin or the mask forming means is stopped. At this time, the transparent sheet belt on the upstream and downstream sides of the mask forming means is given a predetermined tension by the moving roller.

According to the fifth aspect of the present invention, an opening area of the transparent sheet belt facing the exposure means is set to a predetermined area by the shutter moved between the transparent sheet belt at the exposure position and the exposure means. The emitted light is narrowed down to a predetermined area by the opening of the shutter, and is irradiated on a mask formed on the surface of the transparent seat belt.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. 1 to 4 are views showing an embodiment of the optical shaping apparatus according to the present invention. First, the configuration will be described. In FIG. 1, reference numeral 11 denotes a transparent seat belt. The transparent seat belt 11 is made of, for example, transparent polyester having a thickness of 20 to 50 μm which is flexible and transmits light, and is provided with a mechanical force. The mixed material described below adheres with a predetermined adhesive force, and the cured material (the cured layer described later) of the mixed material is easily peeled off. Is being processed. The transparent sheet belt 11 is fed from a supply bobbin 12 removably mounted on a first holder (not shown) and is wound on a winding bobbin 13 similarly mounted on a second holder. The transparent seat belt 11 has driven rollers 14 to 16, a moving roller 17,
18, driving roller 19, driven rollers 20, 21, moving roller 22 ~
24 and a driven roller 25.

The driven rollers 14 to 16, the driven rollers 20 and 21, and the driven roller 25 are fixedly attached to the transparent sheet belt 11 so as to be driven and rotated. The moving roller 17 is interposed between the driven rollers 14 and 15, and the moving roller 18 is interposed between the driven roller 16 and the driven roller 20 so as to be movable in the up-down direction. The driving roller 19 is fixed between the driven rollers 20 and 21,
In the meantime, the transparent sheet belt 11 is sandwiched and driven to rotate counterclockwise in the figure to send the transparent sheet belt 11 downstream. Moving rollers 22-24 are transparent seat belts
The transparent sheet belt 11 is driven to rotate along with and horizontally moves while maintaining the mutual positional relationship to vertically support the transparent sheet belt 11 between the moving rollers 22 and 23. That is, the drive roller
The reference numeral 19 and the driven rollers 20 and 21 constitute a conveying means.

The moving rollers 17 and 18 have a predetermined weight.
26 and 27 are suspended, and a predetermined tension is applied to the transparent sheet belt 11 between the driven rollers 14 and 15, the driven rollers 15 and 16, and the driven rollers 16 and 20, and the driven roller 1
It moves up and down depending on the length of the transparent seat belt 11 between 4 and 15 and between the driven rollers 16 and 20. The driving roller 19
The second holder portion winds the transparent sheet belt 11 sent out to the downstream side by the rotation of the winding bobbin 13 while keeping the tension constant even when the roll diameter of the winding bobbin 13 changes. .

When the movable rollers 17 and 18 move to the upper limit position or the lower limit position shown in the drawing, a roller detection sensor (roller detection means) (not shown) fixed to the apparatus main body detects the movement. When the moving roller 17 moves to the upper limit position, the first holder unit is driven. When the moving roller 17 moves to the lower limit position, the driving is stopped and the transparent sheet belt 11 is fed out from the supply bobbin 12 by a predetermined amount.
On the other hand, when the moving roller 18 moves to the upper limit position, the printer 30 described later is driven, and when the moving roller 18 moves to the lower limit position, the driving is stopped and the transparent sheet belt 11 is sent out by a predetermined amount to the downstream side of the driving roller 19.

Reference numeral 30 denotes a printer. The printer 30 is interposed between the driven rollers 15 and 16 and has a transparent seat belt 11 interposed therebetween.
A known image forming apparatus (for example, a laser printer) that forms a maximum B4 size (A3, 4 size, etc.) image by fixing toner (mask material) on the surface of
This printer 30 is an EWS (Engineering Work Station)
An image corresponding to the cross-sectional shape data transmitted from 31 is formed on the transparent sheet belt 11, and a mask 32 for shaping and shaping the irradiated light is formed. The printer 30 is the same as that shown in FIG.
As shown in (a), when forming the mask 32, a pair of reference marks 33a and 33b are formed at predetermined positions near the downstream side with respect to the formation area 32a of the mask 32. That is, the printer
Reference numeral 30 denotes a mask forming means. Note that the transparent sheet belt 11 is transported while being transported by a transport roller (not shown) provided in the printer 30 main body.

Reference numeral 34 denotes a coating table, and the coating table 34 is a driven roller.
Transparent seatbelt provided and sent downstream of 21
11 is placed on the upper surface side, the upper surface is processed into a high-precision smooth surface and a plurality of holes (not shown) facing the upper surface are perforated, and air is sucked from the holes. The transparent seat belt placed on the upper side
11 is sucked and its surface is positioned and fixed smoothly. Further, when the transparent seat belt 11 is sent out, air is blown out from the holes to release the fixing by suction, and the transparent seat belt 11 is released.
It is designed to float.

Reference numeral 35 denotes a screen, 36 denotes a squeegee, and the screen 35 has a mesh of a predetermined size. The squeegee 36 (for example, made of urethane rubber) slides while pressing the surface of the screen 35. A paste-like material having a predetermined viscosity supplied to a screen 35 by a known screen printing method is adsorbed and fixed on the upper surface (material layer forming position) of the coating table 34 through the mesh of the transparent sheet belt 11 on the back side of the mask 32. It is applied by spreading to cover at least the mask 32 or its forming area 32a and has a thickness of 100
A material layer 37 of μm to 300 μm is formed. That is, the screen 35 and the squeegee 36 constitute a material layer forming unit. When forming the material layer 37 on the surface of the transparent sheet belt 11, the screen 35 descends to a position facing the surface of the transparent sheet belt 11 with a predetermined gap therebetween, and
When the sheet is conveyed, it rises in a direction away from the surface and retracts so as not to contact the material layer 37 formed on the surface of the transparent seat belt 11. The screen 35 is produced by resin-masking the outer peripheral portion of a framed stainless steel wire mesh, and a region through which the material passes is formed by the masking.

The material supplied to the screen 35 is a known photo-curable resin liquid, for example, an uncured resin liquid which is cured by visible light (or may be light in an ultraviolet region or an infrared region) and the like. Mixing a plurality of types of glass beads having a diameter of about 10 to 30 μm, which have a non-shrinking property with respect to exposure to cure an uncured resin liquid and transmit irradiated light energy, at a mixing ratio of 40% to 80%. The material is a paste having a low viscosity and a predetermined viscosity by mixing a plurality of glass beads with an uncured resin liquid. Since this mixed material is obtained by mixing glass beads with the uncured resin liquid, for example, the material layer 37 is applied without flowing even on the surface of the transparent sheet belt 11 held vertically by the moving rollers 22 and 23. (Layer thickness), and is irradiated with light by a light irradiation device 45 described later. For example, when the uncured resin liquid is brought into a semi-cured state, the position of the glass beads is fixed and the material is fixed. The shape of the layer 37 is kept strong. The glass beads are appropriately selected from those having different diameters according to the required modeling accuracy, and the mixing ratio is adjusted. For example, by setting the mixing ratio of the glass beads to 70% to 80%, the exposure time can be shortened, and distortion due to curing shrinkage of the uncured resin liquid can be reduced.

Numeral 38 denotes a glass table. The glass table 38 has a high-precision smooth surface at least on the upper surface side and is hardly damaged, for example, is made of quartz glass, and transmits light irradiated from the lower surface without reflection. As shown in Figure 2
As shown in (b), a reflection portion 38a that reflects incident light from above and shields light from the lower surface is formed on the downstream side of the upper surface. The glass table 38 is fixed to a horizontal moving table 39 that moves with high precision together with the moving rollers 22 to 24.

Reference numeral 41 denotes a molding base, 42 denotes an elevator,
The modeling base 41 is detachably attached to the elevator 42, and the elevator 42 raises and lowers the modeling base 41 so as to approach or separate from the surface of the transparent seat belt 11 and slide in parallel in the width direction thereof. Has become. The elevator 42 has a fiducial mark 33 formed on the transparent seat belt 11 facing the downstream side of the molding base 41.
A mark detection sensor (mark detection means) (not shown) for detecting the positions a and 33b is fixed, and the mark detection sensor is mounted on the reflecting portion 38a of the transparent seat belt 11 which has been placed and moved on the glass base 38. The detection information for stopping the driving of the driving roller 19 and the horizontal moving table 39 by detecting the mark 33a is sent, and the detection information for stopping the driving of the elevator 42 when detecting the mark 33b is sent.

After the molding base 41 is positioned by the elevator 42, the horizontal moving table 39 moves in a direction (right direction in the drawing) away from the coating table 34 while the driving roller 19 is stopped so as not to rotate. A material layer 37 supported vertically between 22 and 23 is conveyed onto the glass table 38 and pressed from the downstream side by the moving roller 22 so as to be in close contact with the glass layer 38 via the transparent sheet belt 11 so that the material layer 37 is brought into contact with the glass table 38. Is positioned in the layer thickness direction. Also, the modeling base 41
Is to support a cured layer 43 of a predetermined shape that is cured by selectively exposing the material layer 37,
After supporting the hardened layer 43, the horizontal moving table 39 moves in the direction of the coating table 34 (left direction in the drawing) while the driving roller 19 is fixed so as not to rotate, and moves the transparent sheet belt 11 on the glass table 38 to the moving roller 22. , 23, the uncured portions of the transparent sheet belt 11 and the material layer 37 are sequentially peeled from the upstream side from the cured layer 43 that separates and supports the transparent sheet belt 11 vertically downward from the upstream side. That is, the moving rollers 22 and 23 constitute a belt peeling unit. When the modeling base 41 supports the lower hardened layer 43 by the previous shaping, the elevator 42 rises by the shaping pitch, and the material layer 37 moves to the lower surface of the hardened layer 43 and the transparent seat belt 11.
Positioning is performed in the layer thickness direction with respect to the surface.

Reference numeral 45 denotes a light irradiation device. The light irradiation device 45 includes a visible light lamp 46, a condenser mirror 47, and a reflection mirror 48, and a material layer 37 is formed via a transparent sheet belt 11 on a molding base 41 and a glass base. When positioned by 38, the light from the visible light lamp 46 is condensed by the condensing mirror 47, and the reflecting mirror 48 is polarized in the direction of the shaping base 41, and is located below the shaping base 41 (exposed position). The belt 32 is irradiated with the light, and the irradiated light is shaped by a mask 32 to selectively expose the material layer 37 through the transparent sheet belt 11 to form a cured layer 43 having a predetermined shape. That is, the light irradiation device 45 constitutes an exposure unit. In addition, the condenser mirror 47 and the reflection mirror 48 of the light irradiation device 45 are configured by cool mirrors that reflect light except for heat rays, and suppress a rise in temperature due to light irradiation.

Reference numeral 50 denotes a shutter. The shutter 50 is located below the glass table 38 and is fixed to the horizontal moving table 39.
As shown in FIGS. 3 (a) and 3 (b), four shutter films 51 cover the lower part of the glass table 38 to block light from the light irradiating device 45 that enters from below the shutter film 51, and to cover the area of the opening 50a. The light only irradiates the transparent seatbelt 11 placed on the upper surface of the glass table. Holes provided on both side ends of the shutter film 51 are engaged with claws 53a of a rotating roller (sprocket) 53, and when the stepping motor 52 rotates the rotating roller 53 in the forward and reverse directions, the leading ends facing each other are close to each other. An opening 50a is formed at a distance.

The opening area and the opening position of the opening 50a formed by the shutter 50 have a margin so that the tip of the shutter film 51 overlaps the edge of the mask 32 of the transparent sheet belt 11 placed on the glass table 38. Thus, the EWS 31 drives and controls the stepping motor. That is, E
As shown in FIG. 4, the WS 31 transmits data to the printer 30 so that the light blocking area of the mask 32 blocks a predetermined amount of marginal light outside the edge of the light transmitting area. The shutter 50 is driven so that the shutter film 51 overlaps the margin of the mask 32, and the opening 50a is formed.
To form The shutter film 51 is made of a thin and flexible material having elasticity, and a frame (not shown) is embedded at the front end so as not to bend when covering the lower part of the glass table 38, and the side end is shuttered. The guide 54 supports and guides.

Reference numeral 55 denotes a suction device, and the suction device 55 is a moving roller.
The moving roller 22 is fixed to the horizontal moving table 39 with the suction port facing upward so as to move together with the vicinity of the transparent sheet belt 11 and the uncured portion of the transparent sheet belt 11 and the material layer 37 from the cured layer 43. When the glass base 38 and the glass base 38 move in the direction of the coating base 34, the uncured mixed material adhering to the hardened layer 43 is moved from the position separated by a predetermined distance from the position separated by a predetermined distance from the suction port, and the excess is sucked. The unnecessary material is removed from the hardened layer 43.

Reference numeral 56 denotes a scraper. The scraper 56 presses the transparent sheet belt 11 against the moving roller 23 and slides the surface of the transparent sheet belt 11 with a predetermined force.
When the material layer 37 is transported between the moving rollers 22 and 23, the material layer 37 slides on the surface of the transparent sheet belt 11 to remove the uncured portion of the material layer 37 that has been peeled off from the cured layer 43 first. Scrape off. The scraper 56 is used to move the material layer 37 to the molding base 41 or the hardened layer 43 so that the moving roller 2
When the material is conveyed onto the glass table 38 from between the positions 2 and 23, the material is separated from the transparent sheet belt 11 in order to prevent the material remaining on the transparent sheet belt 11 from accumulating behind the scraping portion. The material removed by the scraper 56 or the suction device 55 is recovered by a material recovery means (not shown) and automatically supplied to the screen 35 for reuse. The removed material may be stored.

Reference numeral 57 denotes a post cure lamp. The post cure lamp 57 (hereinafter, simply referred to as a PC lamp 57) is fixed to the horizontal moving table 39 adjacent to the right side of the suction device 55, and includes the moving rollers 22 to When the 24 and the glass table 38 move in the same direction as the coating table 34 and move downward in the same direction to open the lower part of the cured layer 43 supported by the molding base 41, light of a predetermined intensity is applied to the cured layer 43. Irradiation and post-curing treatment (so-called post cure).

Next, the operation will be described together with the molding procedure.
First, the horizontal moving table 48 is moved so that the glass table 38 is adjacent to the coating table 34, and the supply bobbin 12 and the winding bobbin 13 are mounted on the first and second holder units. Next, the transparent sheet belt 11 is pulled out from the supply bobbin 12, engaged with the roller groups 14 to 25 and fixed to the winding bobbin 13, and the transparent sheet belt 11 is placed on the upper surface of the coating table 34 and the glass table 38. A predetermined tension is applied to the transparent seat belt 11. Next, an appropriate amount of the mixed material is supplied to the screen 35, and the molding base is supplied to the elevator 42.
Attach 41 and set to the height of the modeling start position.

Next, the EWS 31 drives the stepping motor 52 of the shutter 50 to form the opening 50a. Mask Forming Step (First Step) Then, when modeling is started, the cross-sectional shape data of the three-dimensional object to be modeled is minutely transmitted from the EWS 31 to the printer 30, and the printer 30 is moved by the transport roller. The transparent sheet belt 11 is conveyed, and a mask 32 is provided on the surface thereof and a reference mark is provided near the formation area 32a.
33a and 33b are formed at the print pitch shown in FIG. 2A, and the mask 32 is continuously formed as shown in FIG.

At this time, the transparent sheet belt 11 between the driven rollers 14 and 15 is shortened by the formation of the mask 32 by the printer 30, but the moving roller 17 is detected by the roller detection sensor and the first holder portion is driven. Then, the transparent seat belt 11 is fed out from the supply bobbin 12 by a predetermined amount. On the other hand, the mask 32 between the driven rollers 16 and 20 and the reference marks 33a and 33b
The transparent sheet belt 11 on which is formed is sequentially sent out such that the driving roller 19 rotates and the mask 32 is positioned on the coating table 34.

Therefore, the mask 32 can be formed on the surface of the transparent seat belt 11 without being restricted by the progress of the subsequent steps. The moving roller 17
When the weight detection sensor detects and / or 18, the driving of the printer 30 and / or the first holder is stopped. Further, since the mask 32 is formed on the surface of the transparent seat belt 11, the mask 32 is in close contact with the transparent seat belt 11. Also, since the transparent sheet belt 11 between the driven rollers 15 and 16 forming the mask 32 is given a predetermined tension by the moving rollers 17 and 18 with weights 26 and 27 suspended therefrom,
The mask 32 and the reference marks 33a and 33b are formed with high precision on the stretched transparent seat belt 11.

Material Layer Forming Step (Second Step) Then, the transparent sheet belt 11 on which the mask 32 is placed so as to be positioned on the coating table 34 is sucked from the holes of the coating table 34 to thereby remove the upper surface thereof. And fix it by suction. At this time, the transparent sheet belt 11 on the downstream side of the driven roller 21 is provided with the second
Since a predetermined tension is given by the holder, the surface is positioned smoothly without wrinkling.

Next, the screen 35 is moved to a transparent seat belt.
Lower to the position facing the surface of 11 with a predetermined gap,
The squeegee 36 is slid while pressing the surface of the screen 35 while the mixed material supplied to the screen 35 is extended to the back side of the mask 32 of the transparent seat belt 11 through the mesh to form a material layer having a predetermined area and thickness. Form 37. Since the material layer 37 may be formed to cover the mask 32, the positioning accuracy of the transparent seat belt 11 is not required. Therefore, the material layer 37 is easily formed with high precision on the surface of the transparent seat belt 11 which is easy to handle, and the screen 35
Since there is a predetermined gap from the transparent seat belt 11, there is no need to peel off the screen 35 after forming the material layer 37, and the shape of the material layer 37 does not deteriorate. further,
The mixed material supplied to the screen 35 may be an appropriate amount for forming the material layer 37.

Next, the screen 35 is moved to a transparent seat belt.
The transparent sheet belt 11 is lifted in a direction away from the surface of the substrate 11 and retracted to a position not in contact with the material layer 37, and is suction-fixed to the upper surface by blowing air from the holes of the application table 34.
To release the suction fixation. And the driving roller 19
Is rotated to transport the material layer 37 formed on the surface of the transparent seat belt 11 from the coating table 34 onto the glass table 38.

At this time, the transparent seat belt 11 is
The screen 35 is sent out without resistance because it floats from the upper surface of the screen 35, and since the screen 35 is retracted upward, the shape does not deteriorate due to contact with the material layer 37. Lamination Step (Third Step) Next, when the material layer 37 is transported between the moving rollers 22 and 23,
The mark detection sensor detects the reference mark 33a formed together with the next mask 32, stops the rotation of the driving roller 19 and the movement of the horizontal moving table 39, and moves the material layer 37 to the moving roller 22,
The transparent seatbelt 11 is positioned and supported vertically between the spaces 23. Next, the elevator 42 is slid in the width direction of the transparent seat belt 11 until the mark detection sensor detects the mark 33b.

Therefore, the transparent seat belt 11 is positioned based on the reference mark 33a, and the molding base 41 is positioned based on the reference mark 33b.
The relative positional relationship between the mask 32 of the transparent seat belt 11 and the modeling base 41 for each modeling is made the same. Next, fix the driving roller 19 so that it does not rotate, and
By moving the horizontal moving table 39 rightward in the figure while maintaining the tension of 11, the moving rollers 22 to 24 and the glass table 38
Is moved below the modeling base 41, and the material layer 37 is conveyed onto the glass table 38 from between the moving rollers 22 and 23.

At this time, the material layer 37 is pressed against the shaping base 41 by the moving roller 22 from the downstream side, and is sequentially brought into close contact (contact) with the shaping base 41 via the transparent sheet belt 11 in the layer thickness direction. Is positioned. Therefore, the material layer 37 and the modeling base 41 are brought into close contact without interposing air between the material layer 37 and the modeling base 41. Further, when the modeling base 41 supports the lower hardened layer 43 by the previous shaping, the material layer 37 is pressed against the hardened layer 43 from the downstream side, and is sequentially brought into close contact (contact) with the hardened layer 43 via the transparent sheet belt 11. It is positioned between the glass table 38 and the hardened layer 43 in the layer thickness direction. Exposure Step (Fourth Step) Next, the visible light lamp 46 of the light irradiation device 45 is turned on, and the light of the visible light lamp 46 polarized in the direction of the glass table 38 is narrowed by the opening 50 a of the shutter 50. The light transmitted through the mask 32 is shaped by the mask 32, and the material layer 37 is irradiated through the transparent sheet belt 11 for a predetermined time to selectively expose the material layer 37. And the material layer 37
Is selectively cured to form a cured layer 43 having a predetermined shape and supported by the modeling base 41.

Here, the light for selectively exposing the material layer 37 is shaped by the mask 32 adhered to the surface of the transparent sheet belt 11 and irradiated through the transparent sheet belt 11, so that the optical path to the material layer 37 is short. As a result, the cured layer 43 is formed with high precision. In addition, since the mask 32 and the modeling base 41 or the lower hardened layer 43 are positioned in the same manner for each shaping, the hardened layers 43 are stacked with high accuracy, and a three-dimensional object with high shaping accuracy is formed.

Further, light for exposing the material layer 37 is a shutter.
Since it is squeezed by 50 and shaped by the mask 32,
The irradiation position accuracy of the light by the light irradiation device 45 is not required, and the area to be shielded by the mask 32 is reduced to reduce
, The consumption of the toner can be reduced. Further, since the glass beads are fixed by curing the uncured resin liquid of the material layer 37, the cured layer 43 can be easily strengthened,
The hardened layer 43 has very little distortion due to shrinkage.
Further, the irradiation energy of the light from the light irradiation device 45 can be reduced, or the irradiation time can be shortened. Further, since there is no uncured photocurable resin outside the material layer 37, light can be irradiated without considering the curing depth. In addition, since the heat rays from the visible light lamp 46 are removed by the condenser mirror 47 and the reflection mirror 48, the temperature rise of the transparent seat belt 11 and the material layer 37 is suppressed, and the reduction in dimensional accuracy due to the thermal expansion of the hardened layer 43 is prevented. Is done.

Peeling Step (Fifth Step) Next, the horizontal moving table 39 is moved to the left in the drawing while maintaining the tension of the transparent sheet belt 11 while the driving roller 19 is fixed so as not to rotate, thereby moving the moving roller 22. ~ And the glass table 38 are moved in a direction close to the coating table 34,
The transparent seat belt 11 is pulled vertically downward from the upstream side of the modeling base 41.

Therefore, the transparent seat belt 11 and the material layer 37
The uncured portion is sequentially peeled from the cured layer 43 from the upstream side and is transported between the moving rollers 22 and 23. At this time, the cured layer 43
The transparent sheet belt 11 is sequentially peeled from the upstream side, and the hardened layer 43 is supported by the modeling base 41 without deformation or breakage. At the same time as the transparent sheet belt 11 is peeled off, the suction device 55 that moves with the moving rollers 22 to 24 and the glass table 38
Thus, the uncured mixed material adhering to the modeling base 41 and the cured layer 43 is removed by suction. Therefore, the surplus material is removed and collected from the cured layer 43 that has been exposed and cured to the target shape.

Post-Processing Step Next, the molding base 41 is raised by the elevator 42 by the thickness of the hardened layer to be formed next, and
39 is moved to the left in the figure to turn on the PC lamp 57 moved below the modeling base 41, and the curing layer 43 supported by the modeling base 41 is irradiated with light of a predetermined intensity for a predetermined time to perform post-curing. Process (post cure).

This post-curing process can be performed simultaneously with the formation of the next material layer 37, and the operating efficiency can be improved. At this time, since the uncured mixed material that has adhered to the cured layer 43 before the post-curing process is sucked by the suction device 55, the mixed material adhered by the post-curing process is cured. The shape of the hardened layer 43 does not deteriorate.

After the post-curing treatment of the cured layer 43, the transparent sheet belt 11 is fed by a predetermined amount by the driving roller 19 to convey the material layer 37 on the surface. The uncured material layer 37 separated (separated) from the hardened layer 43 is transferred to the downstream side of the moving roller 23 and the scraper 56 comes into sliding contact with the surface of the transparent sheet belt 11. Scraper
It is scraped and collected by 56. Therefore, the material remaining on the surface of the transparent seat belt 11 is removed and collected, so that waste of the material is eliminated. Further, the used transparent sheet belt 11 is wound on the winding bobbin 13, but since the uncured material layer 37 is removed and the smoothness is restored, the used transparent sheet belt 11 is wound in a cylindrical shape without unevenness and without collapse.

Product take-out step The above-described mask forming step to post-processing step are repeated by the number of layers of the laminate, and a plurality of cured layers 43 supported on the molding base 41 are laminated to form a three-dimensional object as a laminate. Thereafter, the modeling base 41 is removed from the elevator. Then, by mounting the new molding base 41 on the elevator 42, the molding can be continuously performed. The shaped product is post-cured each time the cured layer 43 is formed without being immersed in the material, so that post-treatment such as cleaning is not required, and the product can be used as it is by removing it from the modeling base 41. Therefore, the product can be easily handled, and unmanned operation and continuous operation are possible.

As described above, according to the present embodiment, in the mask forming step, the movable rollers 17 and 18 apply a predetermined tension to the transparent sheet belt 11 so that the transparent sheet belt 11 is in a tensioned state.
The mask 32 and the reference marks 33a and 33b can be formed with high accuracy, and can be sent with high accuracy to a subsequent material forming step or the like. Further, since the roller detecting means detects the positions of the moving rollers 17 and 18 and sends out the transparent sheet belt 11 on the upstream and downstream sides of the printer 30 so as to have a predetermined amount, the mask forming step is not synchronized with the subsequent step. It can be performed independently, and the time of the process can be reduced.

In the material layer forming step, the material layer made of the mixed material is formed on the back side of the mask 32 of the transparent sheet belt 11 placed on the coating table 34 by a screen printing method using a screen 35 and a squeegee 36. Since the material layer 37 is formed, the material layer 37 can be formed to a predetermined thickness with high accuracy using an appropriate amount of material supplied to the screen 35.
Further, since the material layer 37 is formed of the mixed material obtained by mixing inexpensive glass beads with the uncured resin liquid, material costs can be reduced, and deformation due to curing shrinkage and the like can be prevented. Since the material layer 37 may be formed so as to cover the back surface side of the mask 32, positioning accuracy is not required and positioning in the subsequent exposure step is sufficient.

In the laminating step, the transparent sheet belt 11 is positioned in the traveling direction based on the reference mark 33a, and the shaping base 41 is positioned in the width direction based on the reference mark 33b. The relative positional relationship for each molding can be made the same for each molding, and the lower hardened layer 43 and the mask 32 formed earlier can be positioned with high precision.

When positioning the material layer 37 between the glass table 38 and the molding base 41 via the transparent seat belt 11 in the layer thickness direction, the moving roller 22 is attached to the molding base 41 or the previously formed hardened layer 43. As a result, the material layer 37 is pressed down from the downstream side and is brought into close contact with the material layer 37, so that air can be prevented from being trapped and the hardened layer 43 can be laminated with high accuracy. In the exposure step, since the light from the light irradiation device 45 that exposes the material layer 37 by the mask 32 formed and adhered to the surface of the transparent sheet belt 11 is shaped, the optical path to the material layer 37 is shortened and the exposure is performed with high accuracy. be able to. In addition, since the light emitted from the light irradiation device 45 only needs to be irradiated on the mask 32, the irradiation accuracy is not required and an optical system for forming an image is not required.

Further, since the light emitted from the light irradiation device 45 is narrowed by the shutter 50 to the opening area of the opening 50a, the light-shielding area of the mask 32 formed by the printer 30 is reduced to reduce the toner consumption. It is possible to reduce running costs and to operate for a long time. In addition, since the cured layer 43 is laminated by exposing the material layer 37 layer by layer, the exposure can be performed in a short time without unevenness by an inexpensive light source without considering the curing depth.

In the peeling step, when the transparent sheet belt 11 is peeled from the cured layer 43, the transparent sheet belt 11 is vertically separated from the upstream side of the modeling base 41, so that the cured layer 43 is not deformed or damaged. The uncured portion of the material layer 37 adhered to the transparent seat belt 11 can be separated from the cured layer 43. At the same time, since the uncured material layer 37 is suctioned and removed by the suction device 55, even if the uncured material remains in the cured layer 43, it is possible to prevent the shape of the cured layer 43 from being deteriorated in a later step. Can be.

In the post-processing step, P
The C lamp 57 is moved below the hardened layer 43 so that the post-hardening process can be continuously performed. Further, since the uncured portion of the material layer 37 peeled from the cured layer 43 is removed by the scraper 56 before being wound on the winding bobbin 13, the winding bobbin 13 can be easily handled, Since the removed material is recovered, the material can be reused, and waste of the material can be reduced. In addition, the amount of the mixed material to be supplied by changing the size of the screen 35 in accordance with the size of the screen 35 and exchanging it according to the size of the product can be set to an appropriate amount, and the collection amount can be suppressed.

In the product removal process, the molding base 41
Since the molding can be continued only by replacing the, the automation, unmanned operation, and continuous operation can be realized, and the operation efficiency can be improved. Further, each time the cured product 43 is formed without being immersed in the material, post-curing is performed on the molded product, so that post-treatment such as cleaning is not required, and the molded product can be used as it is by removing it from the modeling base 41.

[0064]

According to the first to fifth aspects of the present invention, a mask for shaping light into a predetermined shape is provided on the surface of the transparent seat belt.
After forming a material layer of a predetermined thickness made of a paste-like photocurable material on the back side, and positioning the material layer in the layer thickness direction, the material layer is exposed by light shaped by irradiating light from the mask side. Since a cured layer of a predetermined shape is formed, a mask for shaping light to be exposed can be brought into close contact with a transparent sheet belt to shorten the optical path to the material layer and selectively irradiate, thereby exposing the material layer with high precision. be able to. Therefore, a high-precision three-dimensional object can be formed.

Further, since the light for exposing the material layer only needs to be irradiated to the position where the light of the mask is transmitted, the accuracy of the position for irradiating the light is not required, and no optical system for imaging the light for exposure is required. . Therefore, an apparatus for irradiating light can be manufactured at low cost, and the molding cost of a three-dimensional object can be reduced. Then, since the material layer is formed on the surface of the transparent sheet belt, the material layer can be formed with high precision using, for example, an appropriate amount of a high-viscosity material by, for example, a screen printing method. , And uncured material layers can be separated without deforming the cured layer. In addition, since a cured layer is formed by exposing a material layer having a predetermined thickness,
Since there is no need to consider the curing depth of the material layer, it is possible to perform exposure using a low-cost light source that performs uniform exposure in a short time. Furthermore, since it is not a batch process, continuous automatic operation can be realized. Also, since it is not immersed in the material, cleaning is not required. Therefore, a high-precision three-dimensional object can be formed at low cost.

In particular, according to the third aspect of the present invention, since the reference mark near the mask is detected and the movement of the transparent sheet belt and the molding base is stopped and positioned, the mask and the lower hardened layer are positioned on the reference mark. The cured layer can be laminated with high precision by easily aligning with the reference. Therefore, the image accuracy of the three-dimensional object is improved. According to the fourth aspect of the present invention, the upstream and downstream moving rollers forming the mask move up and down while applying a predetermined tension to the transparent sheet belt, and feed the transparent sheet belt according to its position. Thus, the mask can be formed with high precision, and the transparent seat belt can be moved to a subsequent step without wrinkling. In addition, mask formation can be performed independently without synchronizing with a subsequent step, and the time for the step can be reduced. Therefore, a three-dimensional object with improved modeling accuracy can be modeled at low cost.

According to the fifth aspect of the present invention, the light irradiated on the transparent sheet belt at the exposure position is reduced to a predetermined area.
The light shielding area of the mask for shaping the light can be reduced. Therefore, the consumption of the mask material for forming the mask can be reduced, the running cost can be reduced, and the operation can be performed for a long time.

[Brief description of the drawings]

FIG. 1 is a schematic overall configuration diagram showing an embodiment of an optical shaping apparatus according to the present invention.

FIG. 2 is a view showing a transparent seat belt on which a mask and a reference mark are formed by the mask forming means;
(A) is its top view, (b) is its side view.

3A and 3B are views showing the shutter, wherein FIG. 3A is a plan view thereof, and FIG. 3B is a side view of a main part thereof.

FIG. 4 is a plan view showing a mask formed by the mask forming means.

[Explanation of symbols]

 11 Transparent sheet belt 12 Supply bobbin 13 Take-up bobbin 17, 18 Moving roller 19 Drive roller (conveying means) 20, 21 Follower roller (conveying means) 22, 23 Moving roller (belt peeling means) 26, 27 Weight 30 Printer (mask) Forming means) 32 Mask 33a, 33b Reference mark 34 Coating table 35 Screen (Material layer forming means) 36 Squeegee (Material layer forming means) 37 Material layer 38 Glass table 41 Modeling base 42 Elevator 43 Cured layer 45 Light irradiation device (Exposure means) ) 50 Shutter 50a Opening

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B29C 67/00

Claims (5)

(57) [Claims] An uncured material layer (37) made of a photocurable material is exposed to form a cured layer (43), and the cured layer (43)
In a stereolithography method for forming a three-dimensional object by successively stacking a mask, wherein a mask (32) for shaping light into a predetermined shape is provided on a transparent seat belt.
A first step of forming on the surface of (11), a material layer (37) of a predetermined thickness made of a paste-like photocurable material on the back side of the transparent sheet belt (11) with respect to the mask (32). In the second step of forming, the material layer (37) is sandwiched between the transparent seat belt (11) and the modeling base (41) or the lower cured layer (43) supported by the modeling base (41). A third step of positioning in the layer thickness direction, and irradiating light from the mask (32) side and shaping light onto the positioned material layer (37) via a transparent sheet belt (11) to irradiate the material layer. Exposing (37) to form a cured layer (43) having a predetermined shape, and a transparent sheet belt formed from the cured layer (43) cured by the exposure and supported by the molding base (41).
A stereolithography method, comprising: (11) a fifth step of separating an uncured portion of the material layer (37). 2. An uncured material layer (37) made of a photocurable material is exposed to form a cured layer (43).
Forming means for forming a mask (32) for shading light transmitted therethrough into a predetermined shape on the surface of the transparent seat belt (11) in an optical shaping apparatus for forming a three-dimensional object by sequentially stacking
(30) and a material layer forming means for forming a material layer (37) having a predetermined thickness by extending a paste-like photocurable material on the back side of the transparent seat belt (11) with respect to the mask (32) ( 35, 36), and a molding base (37) between the transparent sheet belt (11) and the material layer (37) or the lower cured layer (43) with the material layer (37) positioned in the layer thickness direction. 41) and irradiating the shaped material with light from the mask (32) side to irradiate the positioned material layer (37) via the transparent sheet belt (11) to expose the material layer (37), Exposure means (45) for forming a cured layer (43) having a shape, and conveyance means (19) for moving the transparent sheet belt (11) in a predetermined direction to convey the material layer (37) to the material layer formation position and the exposure position. , 2
0, 21), the transparent sheet belt (11) and the material layer from the cured layer (43) cured by the exposure and supported on the molding base (41).
Belt peeling means (22, 23) for peeling off the uncured portion of (37)
And a stereolithography device comprising: 3. A mask forming means (30) for forming at least one or more reference marks (33a, 33b) near a mask (32), and a mark for detecting the reference marks (33a, 33b). Detecting means and an elevator (42) to which the modeling base (41) is attached and which moves the modeling base (41) close to or away from the surface of the transparent seat belt (11) and moves parallel to the surface, The transporting means based on information detected by the mark detecting means;
The stereolithography apparatus according to claim 2, wherein the drive of the (19, 20, 21) and the elevator (42) is stopped to position the mask (32) and the modeling base (41). 4. A moving roller (1) that applies a predetermined tension to the transparent sheet belt (11) and moves up and down with the movement of the transparent sheet belt (11) on the upstream and downstream sides of the mask forming means (30).
7, 18), and roller detection means for detecting the moving rollers (17, 18) moved to the upper limit position and the lower limit position, and an unused transparent seat belt ( 3. The optical shaping apparatus according to claim 2, wherein the drive and stop of the supply bobbin (12) for sending out (11) and the mask forming means (30) are controlled. 5. A transparent seat belt located at the exposure position.
(11) and a shutter (50) which is moved between the exposure means (45) and provides a predetermined area to an opening area facing the exposure means (45) side of the transparent sheet belt (11). 50) from the exposure means (45) to the transparent seat belt (1).
3. An optical shaping apparatus according to claim 2, wherein the light applied to 1) is reduced.