JP7797837B2 - Optical molding device and method for manufacturing molded object - Google Patents

Description

The present invention relates to a photolithography device and a method for manufacturing a model.

Stereolithography is a commonly known technique for forming a three-dimensional object from cured resin by irradiating a liquid photocurable resin with light, such as ultraviolet light. Patent Document 1 discloses a so-called controlled liquid level method, in which light corresponding to a cross section (predetermined cross section) of the object at a predetermined height is irradiated through a light-transmitting window provided on the bottom surface of a liquid vat containing the photocurable resin toward a base placed opposite the light-transmitting window, forming a layer of cured resin (cured layer) in the same shape as the predetermined cross section on the underside of the base, and then repeatedly lifting the base a predetermined height above the liquid vat. This process stacks the cured layers to form the desired object.

Japanese Patent Application Laid-Open No. 2020-62841

However, with the conventional controlled liquid level method, the object formed by stacking cured layers is immersed in the photocurable resin in the liquid tank. As a result, the irradiated light can sometimes harden excess photocurable resin, leaving room for improvement in terms of accurately forming the object.

The present invention has been made in consideration of the above, and aims to provide a photopolymerization device and a method for manufacturing a molded object that can mold a molded object with high precision.

In order to solve the above-mentioned problems and achieve the object, the optical shaping device of the present invention comprises a modeling tank that stores photocurable resin and has a light-transmitting section on its bottom surface; a light irradiation section that irradiates the photocurable resin with light that cures through the light-transmitting section; a platform that faces the light-transmitting section, is movable up and down relative to the modeling tank, and holds a model formed by stacking layers that have been cured by irradiating light; and a cylindrically shaped platform that is movable up and down relative to the platform and is arranged on the outside of the platform via an airtight member, and holds the platform. The system includes a partition wall that cooperates with the platform to form an airtight space; an air supply/exhaust unit that supplies and exhausts gas to and from the airtight space; a lifting/lowering control unit that raises and lowers the platform and partition wall, respectively, to form a photocurable resin layer of a predetermined thickness between the bottom surface of the partition wall and the underside of the airtight space and the light-transmitting unit; an air supply/exhaust control unit that operates the air supply/exhaust unit to bring the liquid surface of the photocurable resin layer into contact with the underside of the model; and an irradiation control unit that irradiates the photocurable resin layer from the light irradiation unit with light that corresponds to the cross-sectional shape of the model at a predetermined height, thereby forming a cured layer.

The present invention also relates to a photo-lithography device for modeling, which includes a modeling tank that stores photocurable resin and has a light-transmitting section on its bottom surface, a light irradiation section that irradiates light that cures the photocurable resin through the light-transmitting section, a platform that faces the light-transmitting section and can be raised and lowered relative to the modeling tank, a partition wall that can be raised and lowered relative to the platform, is cylindrical, and is arranged on the outside of the platform via an airtight member, forming an airtight space in cooperation with the platform, and an air supply/exhaust section that supplies and exhausts gas to and from the airtight space. This method for manufacturing an object involves repeatedly performing the following steps: raising and lowering the platform and partition wall to form a photocurable resin layer of a predetermined thickness between the bottom surface of the partition wall and the underside of the airtight space and the light-transmitting section; operating the air supply and exhaust section to bring the liquid surface of the photocurable resin layer into contact with the underside of the model; irradiating the photocurable resin layer with light from the light irradiation section that corresponds to the cross-sectional shape of the model at a predetermined height to form a hardened layer; and lowering the partition wall by a predetermined thickness relative to the platform.

The present invention has the effect of enabling shaped objects to be molded with high precision.

FIG. 1 is a schematic diagram showing the basic configuration of a photo-fabrication apparatus according to the first embodiment. FIG. 2 is a diagram for explaining the steps of the method for manufacturing a shaped object according to the first embodiment. FIG. 3 is a diagram for explaining the steps of the method for manufacturing a shaped object according to the first embodiment. FIG. 4 is a diagram for explaining the steps of the method for manufacturing a shaped object according to the first embodiment. FIG. 5 is a diagram for explaining the steps of the method for manufacturing a shaped object according to the first embodiment. FIG. 6 is a diagram for explaining the procedure of the method for manufacturing a shaped object according to the first embodiment. FIG. 7 is a diagram for explaining the steps of the method for manufacturing a shaped object according to the first embodiment. FIG. 8 is a schematic diagram showing the basic configuration of a photo-fabrication apparatus according to the second embodiment. FIG. 9 is a schematic diagram showing the basic configuration of a photo-fabrication apparatus according to the third embodiment. FIG. 10 is a diagram for explaining the procedure of the method for manufacturing a shaped object according to the third embodiment. FIG. 11 is a diagram for explaining the procedure of the method for manufacturing a shaped object according to the third embodiment. FIG. 12 is a diagram for explaining the procedure of the method for manufacturing a shaped object according to the third embodiment. FIG. 13 is a diagram for explaining the procedure of the method for manufacturing a shaped object according to the third embodiment. FIG. 14 is a diagram for explaining the procedure of the method for manufacturing a shaped object according to the third embodiment. FIG. 15 is a schematic diagram showing the basic configuration of a photo-fabrication apparatus according to the fourth embodiment. FIG. 16 is a diagram for explaining the operation of the suction mechanism of the optical shaping apparatus according to the fourth embodiment.

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Note that the present invention is not limited to these embodiments, and when there are multiple embodiments, it also includes configurations that combine the various embodiments. Furthermore, in the following embodiments, identical parts will be designated by the same reference numerals, and redundant explanations will be omitted.

In addition, in the following description of the embodiments, unless otherwise specified, uncured liquid photocurable resin will be simply referred to as photocurable resin. Furthermore, a photo-fabricated object formed by curing liquid photocurable resin will be referred to as a three-dimensional object or simply as a model. This three-dimensional object is not limited to a finished product in which all of the multiple cured layers to be molded are stacked, but also includes an unfinished product in which only intermediate cured layers have been stacked.

[First embodiment]
Fig. 1 is a schematic diagram showing the basic configuration of a photo-lithography apparatus according to a first embodiment. As shown in Fig. 1, the photo-lithography apparatus 10 includes a modeling tank 11, a platform 12, a partition wall 13, a light irradiation unit 20, and a control unit 30. In this embodiment, the photo-lithography apparatus 10 also includes a chamber 40 and a chamber internal pressure adjustment unit 41.

The modeling tank 11 is dish-shaped with an open top and is capable of storing liquid photocurable resin 1. The modeling tank 11 has a light-transmitting plate (light-transmitting portion) 14 on its bottom. This light-transmitting plate 14 transmits light that cures the photocurable resin 1.

The photocurable resin 1 is the raw material for the three-dimensional object 2 and contains polymerizable compounds such as acrylic compounds and vinyl compounds. It is also preferable that the photocurable resin 1 contains a polymerization initiator that generates radical species upon irradiation with light.

The platform 12 holds the object 2 made from the cured photocurable resin 1, and is positioned above the modeling tank 11, facing the light-transmitting plate 14. The platform 12 is formed in a polygonal plate shape, such as a circular or rectangular plate, and is positioned so that its lower surface 12A is approximately parallel to the light-transmitting plate 14. The platform 12 is also connected to a platform lifting mechanism 15, and is configured to be able to rise and fall relative to the modeling tank 11 by operating this platform lifting mechanism 15. Specifically, the platform 12 can move toward and away from the light-transmitting plate 14, and holds the object 2 molded on its lower surface 12A facing the light-transmitting plate 14.

The partition wall 13 is disposed on the outside of the platform 12 and houses the platform 12 and the model 2 inside. The partition wall 13 is formed in a tubular shape (cylindrical or polygonal tubular shape such as a rectangular tubular shape) that corresponds to the shape of the platform 12. The partition wall 13 is also connected to a partition wall lifting mechanism 16, and is arranged so that it can be raised and lowered relative to the platform 12 by the operation of this partition wall lifting mechanism 16. In other words, the partition wall 13 can be raised and lowered relative to the platform 12.

An airtight member 17 is also arranged on the outer periphery of the platform 12 to seal the gap between the platform 12 and the partition wall 13. This airtight member 17 is an O-ring made of an elastic material such as rubber. The airtight member 17 is biased against the inner surface of the partition wall 13 by its restoring force when elastically deformed, thereby sealing the gap between the platform 12 and the partition wall 13. This airtight member 17 ensures airtightness between the platform 12 and the partition wall 13. Therefore, when the platform 12 and the partition wall 13 are lowered into the photocurable resin 1, a space 3 (airtight space) is formed between the platform 12, the partition wall 13, and the photocurable resin 1.

The light irradiation unit 20 is disposed below the modeling tank 11, i.e., on the opposite side of the platform 12 across the light-transmitting plate 14. The light irradiation unit 20 irradiates the photocurable resin 1 with light L, which cures the photocurable resin 1, through the light-transmitting plate 14. The irradiated light L may be any light capable of curing the photocurable resin 1, such as ultraviolet light or short-wavelength visible light. The light irradiation unit 20 includes a light source 21, such as an ultraviolet lamp, an image forming element 22, a reflecting mirror 23, a projection lens 24, etc.

The light source 21 emits light that is irradiated onto the image-forming element 22, and may be, for example, an ultraviolet lamp. The image-forming element 22 modulates the light according to the shape data for each layer of the object 2 to be formed, and may be, for example, an LCOS (Liquid Crystal On Silicon) device, a digital mirror device (DMD), or a liquid crystal device. The reflecting mirror 23 reflects the light modulated by the image-forming element 22 toward the projection lens 24. The projection lens 24 forms an image using the light reflected by the reflecting mirror 23. Note that the light irradiation unit 20 is not limited to this, and may also be, for example, a laser scanning device that uses a laser light source and mirror drive, or an optical device that uses a reflective or refractive optical system.

The chamber 40 is a container that houses at least the modeling tank 11, platform 12, partition wall 13, light irradiation unit 20, and each lifting mechanism 15, 16, etc., and seals the internal environment from the outside. The chamber internal pressure adjustment unit 41 adjusts the internal pressure of the chamber 40 by introducing gas (e.g., air or nitrogen) into the chamber 40 or discharging gas to the outside of the chamber 40 through piping 42. By fine-tuning the internal pressure of this chamber 40, it is possible to freely adjust the position of the underside of the above-mentioned space 3.

The control unit 30 is an arithmetic processing device, such as a CPU (Central Processing Unit), that is connected to and controls the operation of each component of the optical shaping apparatus 10. The control unit 30 stores a program related to the manufacturing method for manufacturing the object 2, loads this program into memory, and executes the instructions contained in the program. The control unit 30 includes an internal memory (not shown), which is used for temporary storage of data such as programs in the control unit 30.

The control unit 30 includes a lift control unit 31, an irradiation control unit 32, and a chamber internal pressure control unit 33. The lift control unit 31 controls the operation of the platform lifting mechanism 15 and the partition lifting mechanism 16 to control the height positions of the platform 12 and the partition 13, respectively. That is, the lift control unit 31 can raise and lower the platform 12 and the partition 13 in conjunction with each other relative to the modeling tank 11, or raise and lower the platform 12 relative to the partition 13. By raising and lowering the platform 12 and the partition 13, respectively, the lift control unit 31 forms a photocurable resin layer of a predetermined thickness between the light-transmitting plate 14 and the lower surfaces of the partition 13 and the space 3.

The irradiation control unit 32 calculates a light irradiation pattern that indicates the cross-sectional shape of the object at predetermined height intervals, for example, based on the three-dimensional shape data, and controls the light source 21, image forming element 22, etc. to irradiate the photocurable resin with light. Therefore, the irradiation control unit 32 can form a cured layer of a predetermined thickness by irradiating the photocurable resin layer between the lower surface of the space 3 and the light-transmitting plate 14 with light that corresponds to the cross-sectional shape of the object at a predetermined height. The chamber internal pressure control unit 33, for example, monitors the position of the lower surface of the space 3 inside the partition 13 (the liquid level of the photocurable resin) and adjusts the internal pressure of the chamber 40 based on the results. Therefore, the position of the lower surface of the space 3 can be aligned with the lower surface of the partition 13, and the thickness of the photocurable resin layer between the lower surface of the space 3 and the light-transmitting plate 14 can be precisely determined.

Next, a method for manufacturing a molded object according to the first embodiment will be described with reference to FIGS. 2 to 7. These figures schematically illustrate a portion of the optical molding apparatus 10 shown in FIG. 1. First, as shown in FIG. 2, the lifting control unit 31 adjusts the height positions of the platform 12 and the partition wall 13 so that the lower surface 12A of the platform 12 and the lower surface (bottom surface) 13A of the partition wall 13 are flush with each other. Next, the lifting control unit 31 lowers the platform 12 and the partition wall 13, which are positioned higher than the molding tank 11 storing the photocurable resin 1, into the molding tank 11, and positions them so that the lower surface 13A of the partition wall 13 and the light-transmitting plate 14 are spaced a predetermined distance T apart. Here, the predetermined distance T is set to the thickness of one layer of the cured layer to be molded (e.g., several μm to approximately 100 μm). In this case, a photocurable resin layer 1a having a predetermined thickness T, the same as the predetermined distance T, is formed between the platform 12 and the light-transmitting plate 14.

Next, the irradiation control unit 32 calculates an irradiation pattern that indicates the cross-sectional shape of the object 2 at a predetermined height based on the three-dimensional shape data of the object 2 to be molded, and irradiates the photocurable resin layer 1a with light L that corresponds to the cross-sectional shape of the first layer through the light-transmitting plate 14. As a result, the photocurable resin layer 1a hardens to the same shape as the cross-sectional shape of the first layer. Therefore, as shown in Figure 3, a hardened layer 2a of a predetermined thickness T that will become the first layer is held on the platform 12.

Then, as shown in FIG. 4, the lifting control unit 31 raises the platform 12 and the partition wall 13 to a position higher than the modeling tank 11. Next, as shown in FIG. 5, the lifting control unit 31 lowers the partition wall 13 by a predetermined thickness T relative to the platform 12. As a result, the lower surface 13A of the partition wall 13 becomes flush with the lower surface 2aA of the hardened layer 2a, and a space (airtight space) 3 partitioned by the platform 12 and the partition wall 13 is formed around the hardened layer 2a.

Then, the lifting control unit 31 vertically lowers the platform 12 and partition wall 13 into the modeling tank 11 until the predetermined distance T is reached between the lower surface 13A of the partition wall 13 and the light-transmitting plate 14. In this case, the space 3 partitioned by the platform 12 and partition wall 13 becomes an airtight space, and as shown in Figure 6, a photocurable resin layer 1a of a uniform predetermined thickness T is formed between the lower surface 3A of the space 3 and the light-transmitting plate 14.

Here, the lower surface 3A of the space 3 coincides with the liquid level of the photocurable resin layer 1a. The height of this liquid level of the photocurable resin layer 1a may vary depending on the depth and surface area of the photocurable resin 1 in the area accumulated around the partition wall 13. For this reason, in this embodiment, the chamber internal pressure adjustment unit 41 shown in FIG. 1 is used to appropriately adjust the liquid level of the photocurable resin layer 1a. The chamber internal pressure control unit 33, for example, monitors the liquid level of the photocurable resin layer 1a inside the partition wall 13 and, based on the results, adjusts the internal pressure of the chamber 40 so that the photocurable resin layer 1a has a predetermined thickness T. For example, the chamber internal pressure control unit 33 can lower the chamber internal pressure from the initial state to lower the lower surface 3A of the space 3 and reduce the thickness of the photocurable resin layer 1a. By adjusting the internal pressure of the chamber 40 in this way, the position of the lower surface 3A of the space 3 can be aligned with the lower surface 13A of the partition wall 13, and the photocurable resin layer 1a can be brought into contact only with the lower surface 2aA of the cured layer 2a.

Next, as shown in FIG. 6, the irradiation control unit 32 irradiates the photocurable resin layer 1a with light L corresponding to the cross-sectional shape of the second layer through the light-transmitting plate 14. As a result, the photocurable resin layer 1a hardens to the same shape as the cross-sectional shape of the second layer, as shown in FIG. 7. The second layer, having a predetermined thickness T, is stacked on the first layer to form the cured layer 2a. In this manner, in this embodiment, the photocurable resin layer 1a having a predetermined thickness T is formed between the lower surface 13A of the partition wall 13 and the lower surface 3A of the space 3 and the light-transmitting plate 14. This photocurable resin layer 1a is then hardened to the predetermined shape. This allows the thickness of the cured layer 2a to be precisely shaped, and ultimately allows the object 2 to be precisely shaped. Furthermore, in this embodiment, the space 3 can be provided around the previously formed cured layer 2a, thereby preventing the light L irradiated through the light-transmitting plate 14 from curing excess photocurable resin 1.

In this way, the lifting control unit 31 and the irradiation control unit 32 alternately form the photocurable resin layer 1a and the hardened layer 2a, stacking the nth (n is a natural number) hardened layer 2a with the (n+1)th hardened layer 2a, thereby forming the object 2.

As described above, the optical molding device 10 according to the first embodiment comprises a molding tank 11 that stores photocurable resin 1 and has a light-transmitting plate 14 on its bottom surface, a light irradiation unit 20 that irradiates light L through the light-transmitting plate 14 to cure the photocurable resin 1, a platform 12 that faces the light-transmitting plate 14 and can be raised and lowered relative to the molding tank 11, and a cylindrically shaped airtight member 17 that can be raised and lowered relative to the platform 12 and is disposed on the outside of the platform 12. The system includes a partition 13 that cooperates with the platform 12 to form an airtight space 3, an elevation control unit 31 that raises and lowers the platform 12 and partition 13, respectively, to form a photocurable resin layer 1a of a predetermined thickness T between the underside 13A of the partition 13 and the underside 3A of the space 3 and the light-transmitting plate 14, and an irradiation control unit 32 that irradiates the photocurable resin layer 1a from the light irradiation unit 20 with light L that corresponds to the cross-sectional shape of the target object 2 at a predetermined height position, thereby forming a cured layer 2a.

With this configuration, a photocurable resin layer 1a of a predetermined thickness T is formed between the lower surface 13A of the partition wall 13 and the lower surface 3A of the space 3 and the light-transmitting plate 14, and this photocurable resin layer 1a is cured to a predetermined shape, allowing the thickness of the cured layer 2a to be precisely formed, and ultimately the model 2 to be precisely formed. Furthermore, with this configuration, a space 3 can be provided around the previously formed cured layer 2a, preventing the problem of excess photocurable resin 1 being cured by light L irradiated through the light-transmitting plate 14, and allowing the model 2 to be precisely formed.

In addition, the lifting control unit 31 lowers the partition 13 by a predetermined thickness T relative to the platform 12 each time the formation of a hardened layer 2a is completed. Therefore, when the platform 12 and partition 13 are lowered into the modeling tank 11, a photo-curable resin layer 1a of the predetermined thickness T can always be formed between the underside 13A of the partition 13 and the underside 3A of the space 3 and the light-transmitting plate 14. This allows the thickness of the hardened layer 2a to be precisely formed, and ultimately allows the model 2 to be precisely formed.

In addition, the lifting control unit 31 temporarily raises the platform 12 and partition wall 13 above the photocurable resin 1 each time the formation of the cured layer 2a is completed, allowing gas to be introduced inside the platform 12 and partition wall 13, forming an airtight space. This allows the thickness of the cured layer 2a to be precisely formed, and ultimately allows the molded object 2 to be precisely formed.

In addition, the lifting control unit 31 and the irradiation control unit 32 alternately form the photocurable resin layer 1a and the hardened layer 2a, stacking multiple hardened layers 2a on the platform 12 to form the object 2, thereby enabling the object 2 to be formed with high precision.

The optical shaping device 10 also includes a chamber 40 that houses at least the shaping tank 11, platform 12, partition wall 13, and light irradiation unit 20, a chamber internal pressure adjustment unit 41 that adjusts the internal pressure of the chamber 40, and a chamber internal pressure control unit 33 that controls this chamber internal pressure adjustment unit 41. Therefore, by adjusting the internal pressure of the chamber 40, the position of the lower surface 3A of the space 3 can be aligned with the lower surface 13A of the partition wall 13, and the photocurable resin layer 1a can be accurately defined to a predetermined thickness T. This allows the thickness of the cured layer 2a to be precisely formed, and ultimately allows the shaped object 2 to be precisely formed.

Second Embodiment
Next, a photo-fabrication apparatus according to a second embodiment will be described. Fig. 8 is a schematic diagram showing the basic configuration of the photo-fabrication apparatus according to the second embodiment. The same components as those in the above-described embodiment will be assigned the same reference numerals and will not be described again.

In the optical shaping device of the first embodiment described above, a platform 12 and a partition 13 work together to create a space (airtight space) 3 in a modeling tank 11 that stores photocurable resin 1 to accommodate a model 2 composed of stacked cured layers 2a. A photocurable resin layer 1a of a predetermined thickness T, equivalent to one layer, is formed between the underside 3A of this space 3 and a light-transmitting plate 14. This configuration allows the model 2 to be molded with high precision. However, if there is a discrepancy in height between the underside 13A of the partition 13 that forms the space 3 and the underside 2A of the cured model 2, the cured model 2 and the photocurable resin layer 1a will not be able to come into contact, potentially resulting in poor modeling.

For this reason, in this second embodiment, the optical shaping apparatus 110 includes, as shown in FIG. 8, a shaping tank 11, a platform 12, a partition wall 13, a light irradiation unit 20, an air cylinder (air supply/exhaust unit) 50, and a control unit 130. The control unit 130 also includes a lift control unit 31, an irradiation control unit 32, and an air supply/exhaust control unit 133.

The air cylinder 50 is connected via a hose 51 to the space 3 partitioned by the platform 12 and the partition wall 13. The air cylinder 50 has, for example, a cylindrical cylinder body with a piston inside. The air supply and exhaust control unit 133, for example, monitors the liquid level of the photocurable resin layer 1a inside the partition wall 13, and depending on the results, moves the position of the piston in the axial direction to introduce or exhaust gas from the cylinder into or from the space 3. The air supply and exhaust control unit 133 operates the air cylinder 50 to bring the liquid level of the photocurable resin layer 1a into contact with the underside 2A of the model 2.

Next, a method for manufacturing a molded object according to the second embodiment will be described. Here, the operation of the air cylinder 50 will be mainly described. As described above, the lifting control unit 31 and the irradiation control unit 32 alternately form the photocurable resin layer 1a and the hardened layer 2a, and form the molded object 2 by stacking the nth (n is a natural number) hardened layer 2a with the (n+1)th hardened layer 2a.

Once a photocurable resin layer 1a of a predetermined thickness T has been formed between the lower surface 13A of the partition wall 13 and the lower surface 3A of the space 3 and the light-transmitting plate 14, the air supply/exhaust control unit 133 operates the air cylinder 50, as shown in FIG. 8 . Specifically, the air supply/exhaust control unit 133 monitors the liquid level of the photocurable resin layer 1a using a sensor or the like, and expels a predetermined amount of gas from the space 3 using the air cylinder 50, slightly raising the liquid level of the photocurable resin layer 1a and bringing the photocurable resin layer 1a into contact with the lower surface 2A of the already cured object 2. Next, the air supply/exhaust control unit 133 supplies a predetermined amount of gas to the space 3 using the air cylinder 50, reducing the thickness of the photocurable resin layer 1a to the predetermined thickness T. In this case, the photocurable resin layer 1a maintains contact with the lower surface 2A of the already cured object 2 due to surface tension.

For this reason, even if the irradiation control unit 32 is operated in this state to form a new hardened layer 2a, this hardened layer 2a will be stacked to form the object 2, thereby reducing molding defects and enabling the molding of a highly accurate object 2.

As described above, the optical molding device 110 according to the second embodiment comprises a molding tank 11 that stores photocurable resin 1 and has a light-transmitting plate 14 on its bottom surface, a light irradiation unit 20 that irradiates light L to cure the photocurable resin 1 through the light-transmitting plate 14, a platform 12 that faces the light-transmitting plate 14, is movable up and down relative to the molding tank 11, and holds a molded object 2 formed by stacking layers 2a cured by irradiation with light L, and a cylindrically shaped airtight member 17 that can be raised and lowered relative to the platform 12 and is disposed outside the platform 12 to form an airtight space 3 in cooperation with the platform 12. an air cylinder 50 for supplying or discharging gas into or from the space 3; an elevation control unit 31 for raising and lowering the platform 12 and the partition 13, respectively, to form a photocurable resin layer 1a of a predetermined thickness T between the lower surface 13A of the partition 13 and the lower surface 3A of the space 3 and the light-transmitting plate 14; an air supply and exhaust control unit 133 for bringing the liquid surface of the photocurable resin layer 1a into contact with the lower surface 2A of the model 2 by operating the air cylinder 50; and an irradiation control unit 32 for irradiating the photocurable resin layer 1a from the light irradiation unit 20 with light L corresponding to the cross-sectional shape of the model 2 at a predetermined height, to form a cured layer 2a.

With this configuration, a photocurable resin layer 1a of a predetermined thickness T is formed between the lower surface 13A of the partition wall 13 and the lower surface 3A of the space 3 and the light-transmitting plate 14. This photocurable resin layer 1a is then cured to a predetermined shape, allowing the thickness of the cured layer 2a to be precisely shaped, thereby enabling the object 2 to be precisely molded. Furthermore, with this configuration, a space 3 can be provided around the previously molded cured layer 2a, preventing the problem of excess photocurable resin 1 being cured by light L irradiated through the light-transmitting plate 14. This allows the object 2 to be precisely molded. Furthermore, with this configuration, an air cylinder 50 is provided to supply and exhaust gas to the space 3 defined by the platform 12 and the partition wall 13, allowing the liquid level of the photocurable resin layer 1a to be adjusted, maintaining contact between the photocurable resin layer 1a and the lower surface 2A of the already cured object 2. This prevents molding defects and allows the object 2 to be precisely molded.

In addition, the lifting control unit 31, the air supply/exhaust control unit 133, and the irradiation control unit 32 repeatedly perform the formation of the photocurable resin layer 1a, the contact of the liquid surface of the photocurable resin layer 1a with the underside 2A of the object 2, and the formation of the hardened layer 2a, thereby minimizing molding defects and enabling the object 2 to be molded with high precision.

[Third embodiment]
Next, a photo-fabrication apparatus according to a third embodiment will be described. Fig. 9 is a schematic diagram showing the basic configuration of the photo-fabrication apparatus according to the third embodiment. The same components as those in the above-described embodiments are given the same reference numerals, and the description thereof will be omitted.

In the optical shaping apparatuses of the first and second embodiments described above, a platform 12 and a partition wall 13 cooperate to provide a space (airtight space) 3 within a shaping tank 11 storing photocurable resin 1 to accommodate a model 2 composed of stacked curable layers 2a. A photocurable resin layer 1a of a predetermined thickness T, equivalent to one layer, is formed between the underside 3A of this space 3 and a light-transmitting plate 14. With this configuration, it is necessary to lower the partition wall 13 by the predetermined thickness T relative to the platform 12 each time a cured layer 2a is formed. In this case, the predetermined thickness T is set to, for example, a few microns, which may pose a problem in that a precise lifting mechanism is required.

For this reason, in this third embodiment, the optical shaping device 210 includes a shaping tank 11, a platform 12, a light irradiation unit 20, and a control unit 230, as shown in FIG. 9. The control unit 230 also includes an elevation control unit 231 and an irradiation control unit 232.

In this third embodiment, the optical shaping device 210 does not have a partition wall as part of its device configuration, but instead forms a cylindrical partition wall 213 around the object 2 on the platform 12 together with the object 2. The platform 12 cooperates with the formed partition wall 213 to form a space (airtight space) 3.

The lifting control unit 231 also controls the operation of the platform lifting mechanism 15 to control the height position of the platform 12. The lifting control unit 231 raises and lowers the platform 12 on which the partition wall 213 is molded, thereby forming a photocurable resin layer of a predetermined thickness between the bottom surface of the partition wall 213, the lower surface of the space 3, and the light-transmitting plate 14.

The irradiation control unit 232 calculates a light irradiation pattern that indicates the cross-sectional shapes of the object 2 and the partition wall 213 at predetermined height intervals, for example, based on the three-dimensional shape data, and controls the light source 21, image forming element 22, etc. to irradiate the photocurable resin with light. The irradiation control unit 232 can form a cured layer of a predetermined thickness by irradiating the photocurable resin layer between the lower surface of the space 3 and the light-transmitting plate 14 with light that corresponds to each cross-sectional shape at a predetermined height position of the object 2 and the partition wall 213.

Next, a method for manufacturing a molded object according to the third embodiment will be described with reference to Figures 10 to 14. These figures schematically show a portion of the optical molding apparatus 10 shown in Figure 9. First, as shown in Figure 10, the lifting control unit 231 lowers the platform 12, which is positioned higher than the molding tank 11 in which the photocurable resin 1 is stored, into the molding tank 11, and positions it at a position where a predetermined distance T is between the underside 12A of the platform 12 and the light-transmitting plate 14. In this case, a photocurable resin layer 1a of a predetermined thickness T, which is the same as the predetermined distance T, is formed between the platform 12 and the light-transmitting plate 14.

Next, the irradiation control unit 232 calculates an irradiation pattern that indicates the cross-sectional shape of the object 2 and the partition wall 213 at a predetermined height based on three-dimensional shape data of the object 2 to be molded and the cylindrical partition wall 213 that can accommodate the object 2, and irradiates the photo-curable resin layer 1a with light L that corresponds to the cross-sectional shape of the first layer of the object 2 and the partition wall 213 through the light-transmitting plate 14. As a result, the photo-curable resin layer 1a hardens to the same shape as the cross-sectional shape of the first layer of the object 2 and the partition wall 213. Therefore, as shown in FIG. 11, the platform 12 holds hardened layers 2a and 213a of a predetermined thickness T that will become the first layers of the object 2 and the partition wall 213, respectively.

Next, as shown in FIG. 12, the lifting control unit 231 raises the platform 12 and temporarily positions it at a position higher than the modeling tank 11. Here, the hardened layer 2a of the model 2 and the hardened layer 213a of the partition wall 213 are formed to the same height and a predetermined thickness T. As a result, the lower surface 2aA of the hardened layer 2a of the model 2 and the lower surface 213aA of the hardened layer 213a of the partition wall 213 are flush with each other, and a space (airtight space) 3 partitioned by the platform 12 and the partition wall 213 (hardened layer 213a) is formed around the model 2 (hardened layer 2a).

Then, the lifting control unit 231 vertically lowers the platform 12 into the modeling tank 11 until the distance between the lower surface 213A of the partition wall 213 and the light-transmitting plate 14 is a predetermined distance T. In this case, the space 3 partitioned by the platform 12 and the partition wall 213 becomes an airtight space, and as shown in FIG. 13, a photocurable resin layer 1a of a uniform predetermined thickness T is formed between the lower surface 3A of the space 3 and the light-transmitting plate 14.

Next, the irradiation control unit 232 irradiates the photocurable resin layer 1a with light L corresponding to the cross-sectional shape of the object 2 and the second layer of the partition wall 213 through the light-transmitting plate 14. As a result, the photocurable resin layer 1a hardens to the same shape as the cross-sectional shape of the second layer, as shown in FIG. 14, and the second layer of a predetermined thickness T is laminated on the first layer to form the cured layers 2a, 213a. In this embodiment, a photocurable resin layer 1a of a predetermined thickness T is formed between the light-transmitting plate 14 and the lower surface 213aA of the partition wall 213 and the lower surface 3A of the space 3, which are molded together with the object 2, and the lower surface 3A. This photocurable resin layer 1a is then cured into the predetermined shape. This allows the thicknesses of the cured layers 2a, 213a of the object 2 and the partition wall 213 to be precisely formed, and ultimately allows the object 2 to be precisely formed. Furthermore, in this embodiment, a space 3 can be provided around the previously formed cured layer 2a, preventing the problem of excess photocurable resin 1 being cured by light L irradiated through the light-transmitting plate 14. Furthermore, in this embodiment, the partition 213 is formed together with the model 2, eliminating the need to provide a separate partition around the platform 12, and simplifying the device configuration of the optical modeling device 210.

The lifting control unit 231 and the irradiation control unit 232 alternately form the photocurable resin layer 1a and the hardened layers 2a, 213a of the object 2 and the partition wall 213, stacking the nth (n is a natural number) hardened layer 2a, 213a onto the nth+1th hardened layer 2a, 213a, thereby forming the object 2 and the partition wall 213.

As described above, the optical molding device 210 according to the third embodiment comprises a molding tank 11 that stores photocurable resin 1 and has a light-transmitting plate 14 on its bottom surface, a light irradiation unit 20 that irradiates light L through the light-transmitting plate 14 to cure the photocurable resin 1, and a cylindrical partition wall 213 that faces the light-transmitting plate 14 and can be raised and lowered relative to the molding tank 11, and that holds the cylindrical partition wall 213 that is formed around the object 2 together with the object 2 by irradiation with light L, and cooperates with the partition wall 213 to form an air gap. The system includes a platform 12 that forms a dense space 3, an elevation control unit 231 that raises and lowers the platform 12 to form a photocurable resin layer 1a of a predetermined thickness T between the lower surface 213A of the partition 213 and the lower surface 3A of the space 3 and the light-transmitting plate 14, and an irradiation control unit 232 that irradiates the photocurable resin layer 1a from the light irradiation unit 20 with light L that corresponds to the cross-sectional shape of the model 2 and the partition 213 at a predetermined height, thereby forming each cured layer 2a, 213a.

With this configuration, a photocurable resin layer 1a of a predetermined thickness T is formed between the light-transmitting plate 14 and the lower surfaces 213aA and 3A of the partition walls 213 and the space 3, which are molded together with the object 2. This photocurable resin layer 1a is then cured to a predetermined shape. This allows the thicknesses of the cured layers 2a and 213a of the object 2 and the partition walls 213 to be precisely formed, and ultimately allows the object 2 to be precisely molded. Furthermore, in this embodiment, a space 3 can be provided around the previously molded cured layer 2a, preventing the problem of excess photocurable resin 1 being cured by light L irradiated through the light-transmitting plate 14. Furthermore, in this embodiment, because the partition walls 213 are molded together with the object 2, there is no need to provide a separate partition around the platform 12, simplifying the configuration of the optical shaping device 210.

In addition, the lifting control unit 231 temporarily raises the platform 12 above the photocurable resin 1 each time the formation of the cured layers 2a, 213a is completed, allowing gas to be introduced inside the partition wall 213 formed on the platform 12, forming an airtight space. This allows the thickness of the cured layers 2a, 213a to be precisely formed, and ultimately allows the model 2 to be precisely formed.

In addition, the lifting control unit 231 and the irradiation control unit 232 alternately form the photocurable resin layer 1a and the cured layers 2a and 213a, stacking multiple cured layers 2a and 213a on the platform 12 to form the object 2 and partition wall 213. This simplifies the device configuration of the optical molding device 210 while enabling the object 2 to be precisely molded.

In addition, the lower surface 2A of the object 2 and the lower surface 213A of the partition wall 213 are always flush with each other, making it easy to mold the object 2 with high precision.

[Fourth embodiment]
Next, a photo-fabrication apparatus according to a fourth embodiment will be described. Fig. 15 is a schematic diagram showing the basic configuration of the photo-fabrication apparatus according to the fourth embodiment. Fig. 16 is a diagram for explaining the operation of the suction mechanism of the photo-fabrication apparatus according to the fourth embodiment. The same components as those in the above-described embodiments are given the same reference numerals, and their description will be omitted.

In the optical molding apparatuses of the first and second embodiments described above, a platform 12 and a partition 13 cooperate to provide a space (airtight space) 3 in a molding tank 11 that stores photocurable resin 1 to accommodate a molded object 2 composed of stacked cured layers 2a. A photocurable resin layer 1a of a predetermined thickness T, equivalent to one layer, is formed between the underside 3A of this space 3 and a light-transmitting plate 14. This configuration allows the molded object 2 to be molded with high precision. However, if, for example, uncured or semi-cured photocurable resin remains in the previously cured molded object 2, this remaining uncured photocurable resin may also be cured when the next cured layer is cured, potentially making it impossible to mold with high precision.

For this reason, in this fourth embodiment, the optical shaping apparatus 310 includes a shaping tank 11, a platform 12, a light irradiation unit 20, a suction mechanism 60, and a control unit 330, as shown in FIG. 15. The control unit 330 also includes a lift control unit 231, an irradiation control unit 232, and a suction control unit 333.

The suction mechanism 60 generates negative pressure to suck and remove uncured photocurable resin adhering to the model 2. As shown in Figure 15, the suction mechanism 60 includes a dish 61 with an open top, a suction unit 62 connected to the dish 61 via a hose 63 and generating negative pressure within the dish 61, and a movement mechanism 64 that moves the dish 61, for example, horizontally.

In this fourth embodiment, similar to the third embodiment, the optical shaping device 310 does not include a partition wall as part of its device configuration, but instead molds a cylindrical partition wall 313 around the object 2 on the platform 12 together with the object 2. The platform 12 cooperates with the molded partition wall 313 to form a space (airtight space) 3. This partition wall 313 is molded integrally with the object 2. The molding procedure for the object 2 and the partition wall 313 is the same as that described in the third embodiment. Note that because this partition wall 313 is integral with the target object 2, the final step is to separate the partition wall 313 from the object 2.

On the other hand, the dish portion 61 of the suction mechanism 60 is formed to be the same size as the partition wall 313 described above. As shown in FIG. 16, when the suction mechanism 60 is placed below the platform 12 and the platform 12 is lowered, the partition wall 313 is sandwiched between the platform 12 and the dish portion 61. As described above, the partition wall 313 is molded integrally with the model 2, so the model 2 is supported by the platform 12 and the dish portion 61 via the partition wall 313. Therefore, the partition wall 313 also functions as a support for supporting the model 2.

Furthermore, in this configuration, when the partition wall 313 is sandwiched between the platform 12 and the dish portion 61, the edge of the dish portion 61 abuts against the lower surface (bottom surface) 313A of the partition wall 313, forming a closed space. Therefore, by operating the suction unit 62, a negative pressure can be created within this closed space, and uncured photocurable resin 70 adhering to the model 2 can be easily sucked and removed.

As described above, the optical molding device 310 according to the fourth embodiment comprises a molding tank 11 that stores photocurable resin 1 and has a light-transmitting plate 14 on its bottom surface, a light irradiation unit 20 that irradiates light L through the light-transmitting plate 14 to cure the photocurable resin 1, a platform 12 that faces the light-transmitting plate 14 and can be raised and lowered relative to the molding tank 11, and that holds a cylindrical partition wall 313 that is formed around the object 2 together with the object 2 by irradiation with light L, forming an airtight space 3 in cooperation with the partition wall 313, and a device that suctions and removes uncured photocurable resin 70 adhering to the object 2. The system includes a suction mechanism 60, an elevation control unit 231 that raises and lowers the platform 12 to form a photocurable resin layer 1a of a predetermined thickness T between the bottom surface 313A of the partition 313 and the lower surface 3A of the space 3 and the light-transmitting plate 14, an irradiation control unit 232 that irradiates the photocurable resin layer 1a from the light irradiation unit 20 with light L that corresponds to the cross-sectional shape of the model 2 and the partition 313 at a predetermined height, thereby forming an integrated cured layer, and a suction control unit 333 that is positioned below the platform 12 and activates the suction mechanism 60 when the platform 12 is positioned above the photocurable resin 1a.

With this configuration, a photocurable resin layer 1a of a predetermined thickness T is formed between the lower surface 313A of the partition 313 and the lower surface 3A of the space 3 and the light-transmitting plate 14. This photocurable resin layer 1a is then cured to a predetermined shape, allowing the thickness of each cured layer of the object 2 and the partition 313 to be precisely formed, and ultimately allowing the object 2 to be precisely formed. Furthermore, with this configuration, a space 3 can be provided around the cured layer of the previously formed object 2, preventing the problem of excess photocurable resin 1 being cured by light L irradiated through the light-transmitting plate 14, and allowing the object 2 to be precisely formed. Furthermore, when the platform 12 is positioned above the photocurable resin 1, a suction mechanism 60 is activated below the platform 12 to suck and remove uncured photocurable resin 70 adhering to the object 2. This prevents the uncured photocurable resin 70 adhering to the object 2 from being cured separately, allowing the object 2 to be precisely formed.

The partition wall 313 is molded integrally with the model 2 and is sandwiched between the dish portion 61 of the suction mechanism 60 and the platform 12 while the suction mechanism 60 is operating, functioning as a support for the model 2. This makes it easy to prevent the model 2 from detaching from the platform 12, at least during the suction operation.

The suction mechanism 60 has a dish portion 61 with an open top, which abuts against the underside 313A of the partition wall 313 to form a closed space. When the suction portion 62 is activated, a negative pressure is created within this closed space, making it easy to suck in and remove uncured photocurable resin 70 adhering to the model 2.

In addition, the lifting control unit 231, irradiation control unit 232, and suction control unit 333 repeatedly perform the formation of the photocurable resin layer 1a, the formation of the cured layer, and the suction of the uncured photocurable resin 70, stacking multiple cured layers on the platform 12 to form the object 2 and partition wall 313. This simplifies the device configuration of the optical shaping device 310 while enabling the object 2 to be formed with high precision.

So far, the optical shaping apparatus and method for manufacturing a shaped object according to the present invention have been described, but they may be implemented in a variety of different forms other than the above-described embodiments. Furthermore, the configurations of these embodiments may be combined as appropriate. For example, the chamber 40, chamber internal pressure adjustment unit 41, and chamber internal pressure control unit 33 of the first embodiment may be combined with the optical shaping apparatuses according to the second to fourth embodiments, or the air cylinder 50 and air supply/exhaust control unit 133 of the second embodiment may be combined with the optical shaping apparatuses according to the first, third, and fourth embodiments. Furthermore, the suction mechanism 60 and suction control unit 333 of the fourth embodiment may be combined with the optical shaping apparatuses according to the first to third embodiments.

Furthermore, each component of the illustrated optical shaping device is a functional concept and does not necessarily have to be physically configured as shown. In other words, the specific form of each device is not limited to that shown, and all or part of it may be functionally or physically distributed or integrated in any unit depending on the processing load and usage status of each device.

The configuration of the control unit of the optical shaping device is realized, for example, as software, such as a program loaded into memory. In the above embodiment, it was described as a functional block realized by the cooperation of these hardware and software. In other words, these functional blocks can be realized in various ways, using only hardware, only software, or a combination of both.

1 Photocurable resin 1a Photocurable resin layer 2 Three-dimensional structure (modeled object)
2a Hardened layer 3 Space (airtight space)
3A Lower surface 10, 110, 210, 310 Stereolithography device 11 Modeling tank 12 Platform 13, 213, 313 Partition wall 13A, 213A, 313A Lower surface (bottom surface)
14 Light-transmitting plate (light-transmitting part)
15 Platform lifting mechanism 16 Partition wall lifting mechanism 17 Airtight member 20 Light irradiation unit 21 Light source 22 Image forming element 23 Reflection mirror 24 Projection lens 30, 130, 230, 330 Control unit 31, 231 Lifting control unit 32, 232 Irradiation control unit 33 Chamber internal pressure control unit 40 Chamber 41 Chamber internal pressure adjustment unit 50 Air cylinder (supply/exhaust unit)
60 Suction mechanism 61 Dish portion 62 Suction portion 63 Hose 64 Moving mechanism 70 Uncured photocurable resin 133 Air supply/exhaust control portion 333 Suction control portion

Claims (5)

a modeling tank that stores a photocurable resin and has a light-transmitting portion on its bottom surface;
a light irradiation unit that irradiates light that cures the photocurable resin through the light transmission unit;
a platform facing the light transmitting unit, capable of moving up and down relative to the modeling tank, and holding a model formed by stacking layers cured by the irradiation of light;
a partition wall that is movably raised and lowered relative to the platform, that is formed in a cylindrical shape, that is disposed outside the platform via an airtight member, and that cooperates with the platform to form an airtight space;
an air supply/exhaust unit that supplies or exhausts gas to or from the airtight space;
a lifting control section that lifts and lowers the platform and the partition wall, respectively, to form a photocurable resin layer of a predetermined thickness between the bottom surface of the partition wall, the lower surface of the airtight space, and the light transmitting section;
an air supply/exhaust control unit that operates the air supply/exhaust unit to bring the liquid surface of the photocurable resin layer into contact with the bottom surface of the model;
an irradiation control unit that irradiates the photocurable resin layer with the light corresponding to the cross-sectional shape of the object at a predetermined height from the light irradiation unit to form the cured layer; and
A photolithography apparatus comprising: The lift control unit, each time the formation of the hardened layer is completed,
The optical shaping apparatus according to claim 1 , wherein the partition wall is lowered by the predetermined thickness relative to the platform. The optical shaping apparatus of claim 2, wherein the elevation control unit temporarily raises the platform and the partition wall above the photocurable resin. The optical shaping apparatus described in any one of claims 1 to 3, wherein the elevation control unit, the air supply/exhaust control unit, and the irradiation control unit repeatedly perform the formation of the photocurable resin layer, contact of the liquid surface of the photocurable resin layer with the underside of the model, and formation of the cured layer. a light irradiation unit that irradiates light that cures the photocurable resin through the light transmission unit; a platform that faces the light transmission unit and is movable up and down relative to the modeling tank; a partition wall that is movable up and down relative to the platform, is formed in a cylindrical shape, and is disposed outside the platform via an airtight member, and forms an airtight space in cooperation with the platform; and an air supply/exhaust unit that supplies and exhausts gas to and from the airtight space,
raising and lowering the platform and the partition wall, respectively, to form a photocurable resin layer of a predetermined thickness between the bottom surface of the partition wall, the lower surface of the airtight space, and the light transmitting portion;
bringing the liquid surface of the photocurable resin layer into contact with the bottom surface of the object by operating the air supply and exhaust unit;
irradiating the photocurable resin layer with the light corresponding to a cross-sectional shape of the object at a predetermined height from the light irradiation unit to form a cured layer;
and lowering the partition wall by the predetermined thickness relative to the platform.