Patent Publication Number: US-2019184638-A1

Title: Three-dimensional object shaping method and apparatus

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the priority benefit of Japanese Patent Application No. 2018-149658, filed on Aug. 8, 2018, and Japanese Patent Application No. 2017-242153, filed on Dec. 18, 2017. The entirety of each of the above-mentioned patent applications is hereby incorporated by reference herein and made a part of this specification. 
     TECHNICAL FIELD 
     This disclosure relates to a method and an apparatus for shaping a three-dimensional object. 
     DESCRIPTION OF THE BACKGROUND ART 
     There are known three-dimensional object shaping apparatuses that have been developed to obtain three-dimensional objects (For example, JP 2016-7711 A). In a three-dimensional object shaping method using such a three-dimensional object shaping apparatus, a modeling material used to form the three-dimensional object and a support material that serves to support the modeling material are ejected from a head to a working plane and stacked in layers. Then, the support material is later removed to complete shaping of a three-dimensional object. Other known methods may be employed, for example, a method for shaping a three-dimensional object by sintering particles of a powdery material made of, for example, a metal under laser light, or a method for shaping a three-dimensional object by binding particles of a powdery material made of, for example, a resin using a binder. 
     SUMMARY 
     In the three-dimensional object shaping methods described earlier, the modeling material may be layered in a flat shape to form a block-shaped object or an object with a flat portion like a top plate of a table, or the modeling material may be layered in a linear shape or a bar-like shape for certain shapes of the three-dimensional object to be obtained. Then, the modeling material may be partly deformed under stress. Such deformation of the modeling material may cause the three-dimensional object to degrade in quality or cause the three-dimensional object to be poorly shaped in case any deformed part contacts the head during an object-shaping operation. 
     What is disclosed herein was accomplished to address the issues of the known art. A method and an apparatus for shaping a three-dimensional object are provided that suppress a risk of a three-dimensional object being deformed. 
     This disclosure provides a method for shaping a three-dimensional object on a working plane, including: a three-dimensional object shaping step of stacking a modeling material and a support material in layers on the working plane, the modeling material constituting the three-dimensional object, the support material serving to support the modeling material; and a deformation restrainer shaping step of forming a deformation restrainer away from the working plane and in contact in at least a part thereof with the support material, the deformation restrainer being a portion distinct from a target portion formed of the modeling material in the three-dimensional object shaping step and serving to generate a force that acts against stress causing the target portion to deform. 
     According to the method thus configured, the deformation restrainer may serve to generate a force that acts against stress-driven deformation, if any, of the target portion formed of the modeling material. This may suppress the risk of the target portion being deformed. Because the deformation restrainer at least partly stays in contact with the support material, the contact with the support material may ensure that a force is generated against possible deformation of the target portion. Further, the deformation restrainer formed in contact with the three-dimensional object may suppress the risk of the target portion being deformed regardless of any shape of the three-dimensional object. 
     In the three-dimensional object shaping method, the deformation restrainer shaping step may form a connector that allows the deformation restrainer to connect in at least a thinned part thereof to the target portion. 
     This may allow the deformation restrainer to receive, through the connector, stress causing the target portion to deform and thus further ensures that a force is generated against such deformation-causing stress. 
     In the three-dimensional object shaping method, the deformation restrainer shaping step may form a base of the deformation restrainer on a side opposite to the target portion across the connector, so that the connector is tapered and thinner toward the target portion. 
     According to this configuration, the connector has a part progressively thinner toward the target portion. After the object is completed, therefore, the thinned part may facilitate removal of the deformation restrainer that is no longer necessary. 
     In the three-dimensional object shaping method, the deformation restrainer shaping step may form the base so as to have a shorter dimension in a planar direction in which ends of the base formed on the support material possibly detach and warp away from the support material. 
     According to this configuration, any possible warp of the end of the base from the support material may be prevented by forming the base to be shorter in a dimension in the planar direction in which the end of the base possibly warp and detach from the support material. 
     The three-dimensional object shaping method may further include a removing step of removing the deformation restrainer connected to the target portion from the three-dimensional object after the three-dimensional object is formed of the modeling material and the support material is removed. 
     According to this configuration, the three-dimensional object may be readily obtained by removing the deformation restrainer after the support material is removed from the object. 
     In the three-dimensional object shaping method, the deformation restrainer shaping step may form the deformation restrainer in a shape having a portion formed along a direction intersecting with the working plane. 
     According to this configuration, such a part formed in the deformation restrainer along a direction intersecting with the working plane may prevent the deformation restrainer from extending along the working plane. As a result, the support material used may be economized. 
     In the three-dimensional object shaping method, the deformation restrainer shaping step may form the deformation restrainer in a shape having a flat portion parallel to the working plane. 
     According to this configuration, the flat portion may enhance the contact with the support material and thereby ensure that a force is generated against possible deformation of the target portion. 
     In the three-dimensional object shaping method, the deformation restrainer shaping step may form at least two deformation restrainers in a direction intersecting with the working plane. One of the two deformation restrainers closer to the working plane may have a shape with a flat portion parallel to the working plane, while the other one of the two deformation restrainers farther from the working plane may have a shape with a portion formed along a direction intersecting with the working plane. 
     By providing at least two deformation restrainers, the deformation restrainers may be prevented from extending along the working plane, and a force may be surely generated against possible deformation of the target portion. 
     In the three-dimensional object shaping method, the deformation restrainer shaping step may form the deformation restrainer using the modeling material. 
     Using the modeling material to form the deformation restrainer may save additional labor of preparing a dedicated material for the deformation restrainer. 
     In the three-dimensional object shaping method, the deformation restrainer may have a higher degree of hardness than layers of the support material. 
     According to this configuration, the deformation restrainer thus harder than layers of the support material may serve to prevent unwanted penetration when deformation of the target portion occurs. 
     In the three-dimensional object shaping method, the target portion may have a higher degree of hardness than layers of the support material. 
     While the target portion, if deformed, is possibly detached from the support material, the target portion formed of the modeling material harder than the support material may be unlikely to detach from the support material. 
     This disclosure further provides a method for shaping a three-dimensional object on a working plane, including: a three-dimensional object shaping step of stacking a powdery material in layers on the working plane and repeatedly irradiating the layers with laser light appropriate for shape-related data to form the three-dimensional object; and a deformation restrainer shaping step of forming, simultaneously with the formation of the three-dimensional object, a deformation restrainer in contact in at least a part thereof with the three-dimensional object, the deformation restrainer being a portion distinct from a target portion of the three-dimensional object formed in the three-dimensional object shaping step and serving to generate a force that acts against stress causing the target portion to deform. 
     According to the method thus configured, the deformation restrainer may serve to generate a force that acts against stress-driven deformation, if any, of the target portion when the three-dimensional object is obtained by stacking a powdery material in layers on the working plane and repeatedly irradiating the layers with laser light appropriate for shape-related data. This may suppress the risk of the target portion being deformed. 
     This disclosure further provides a method for shaping a three-dimensional object on a working plane, including: a three-dimensional object shaping step of stacking a powdery material in layers on the working plane and ejecting a binder material appropriate for shape-related data to the powdery material to form the three-dimensional object; and a deformation restrainer shaping step of forming, simultaneously with the formation of the three-dimensional object, a deformation restrainer in contact in at least a part thereof with the three-dimensional object, the deformation restrainer being a portion distinct from a target portion of the three-dimensional object formed in the three-dimensional object shaping step and serving to generate a force that acts against stress causing the target portion to deform. 
     According to the method thus configured, the deformation restrainer may serve to generate a force that acts against stress-driven deformation, if any, of the target portion when the three-dimensional object is obtained by stacking a powdery material in layers on the working plane and ejecting a binder material appropriate for shape-related data to the powdery material. This may suppress the risk of the target portion being deformed. 
     This disclosure further provides a method for shaping a three-dimensional object on a working plane, including: a three-dimensional object shaping step of stacking a modeling material and a support material in layers on the working plane, the modeling material constituting the three-dimensional object, the support material serving to support the modeling material; and a deformation restrainer shaping step of forming a deformation restrainer in contact in at least a part thereof with the working plane and in contact in at least a part thereof with the support material, the deformation restrainer being a portion distinct from a target portion formed of the modeling material in the three-dimensional object shaping step and serving to generate a force that acts against stress causing the target portion to deform. 
     According to this configuration, the deformation restrainer in contact in at least a part thereof with the working plane may more effectively generate a force that acts against the deformation-causing stress. 
     This disclosure further provides a three-dimensional object shaping apparatus configured to shape a three-dimensional object on a working plane, including: an inkjet ejection unit that ejects a modeling material, a support material, and a deformation restrainer material to the working plane, the modeling material constituting the three-dimensional object, the support material serving to support the modeling material, the deformation restrainer material forming a deformation restrainer, the deformation restrainer being a portion distinct from a target portion formed of the modeling material and serving to generate a force that acts against stress causing the target portion to deform; and a controller that prompts the inkjet ejection unit to form the deformation restrainer away from the working plane and in contact in at least a part thereof with the support material at a time of the target portion being formed. 
     According to the method thus configured, the deformation restrainer may serve to generate a force that acts against stress-driven deformation, if any, of the target portion formed of the modeling material. This may suppress the risk of the target portion being deformed. Because the deformation restrainer at least partly stays in contact with the support material, the contact with the support material may ensure that a force is generated against any deformation of the target portion in three-dimensional directions. Further, the deformation restrainer formed in contact with the three-dimensional object may suppress the risk of the target portion being deformed regardless of any shape of the three-dimensional object. The risk of the target portion being deformed may be accordingly reduced, and the object-shaping operation may be smoothly performed. 
     This disclosure further provides a three-dimensional object shaping apparatus configured to shape a three-dimensional object on a working plane, including an object shaping unit that stacks a powdery material in layers on the working plane and repeatedly irradiating the layers with laser light appropriate for shape-related data to form the three-dimensional object and a deformation restrainer, the deformation restrainer being a portion distinct from a target portion of the three-dimensional object and serving to generate a force that acts against stress causing the target portion to deform; and a controller that prompts the object-shaping unit to form, simultaneously with the formation of the three-dimensional object, the deformation restrainer in contact in at least a part thereof with the three-dimensional object at a time of the target portion being formed. 
     According to the apparatus thus configured to form the three-dimensional object by stacking a powdery material in layers on the working plane and repeatedly irradiating the layers with laser light appropriate for shape-related data, the risk of the target portion being deformed may be effectively reduced, which may allow the object-shaping operation to be smoothly carried out. 
     This disclosure further provides a three-dimensional object shaping apparatus configured to shape a three-dimensional object on a working plane, including an object shaping unit that stacks a powdery material in layers on the working plane and ejecting a binder material appropriate for shape-related data to the powdery material to form the three-dimensional object and a deformation restrainer, the deformation restrainer being a portion distinct from a target portion of the three-dimensional object and serving to generate a force that acts against stress causing the target portion to deform; and a controller that prompts the object-shaping unit to form, simultaneously with the formation of the three-dimensional object, the deformation restrainer in contact in at least a part thereof with the three-dimensional object at a time of the target portion being formed. 
     According to the apparatus thus configured to form the three-dimensional object by stacking a powdery material in layers on the working plane and ejecting a binder material appropriate for the shape-related data to the powdery material, the risk of the target portion being deformed may be effectively reduced, and the object-shaping operation may be smoothly performed. 
     This disclosure provides a three-dimensional object shaping method and apparatus that may successfully suppress the risk of a three-dimensional object being deformed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic drawing of a three-dimensional object shaping apparatus according to an embodiment of this disclosure. 
         FIG. 2  is a drawing of a surface side of an ejection unit from which ink droplets are ejected. 
         FIG. 3  is a drawing of a three-dimensional object formed on a working plane by the ejection unit and a deformation restrainer. 
         FIG. 4  is another drawing of the three-dimensional object formed on the working plane by the ejection unit and the deformation restrainer. 
         FIG. 5  is an enlarged view of a portion encircled with a broken line in  FIG. 4 . 
         FIG. 6  is a functional block diagram of a controller. 
         FIG. 7  is a flow chart of an operation carried out by the three-dimensional object shaping apparatus. 
         FIG. 8  is a drawing that illustrates a stage in the operation carried out by the three-dimensional object shaping apparatus. 
         FIG. 9  is a drawing that illustrates a stage in the operation carried out by the three-dimensional object shaping apparatus. 
         FIG. 10  is a drawing that illustrates a stage in the operation carried out by the three-dimensional object shaping apparatus. 
         FIG. 11  is a drawing of an exemplified deformation of the three-dimensional object. 
         FIG. 12  is a drawing of a modified example of the three-dimensional object formed on the working plane and the deformation restrainer. 
         FIG. 13  is a drawing of a modified example of the three-dimensional object formed on the working plane and the deformation restrainer. 
         FIG. 14  is a drawing of a modified example of the three-dimensional object formed on the working plane and the deformation restrainer. 
         FIG. 15  is a drawing that illustrates an example of the deformation restrainer. 
         FIG. 16  is a drawing that illustrates an example of the deformation restrainer. 
         FIG. 17  is a drawing that illustrates an example of the deformation restrainer. 
         FIG. 18  is a drawing that illustrates an example of the deformation restrainer. 
         FIG. 19  is a drawing that illustrates an example of the deformation restrainer. 
         FIG. 20  is a drawing that illustrates an example of the deformation restrainer. 
         FIG. 21  is a drawing of a three-dimensional object shaping method. 
         FIG. 22  is a drawing of another three-dimensional object shaping method. 
         FIG. 23  is a drawing of yet another three-dimensional object shaping method. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     Embodiments of a three-dimensional object shaping method and apparatus disclosed herein are hereinafter described in detail referring to the accompanying drawings. This disclosure includes but is not limited to the embodiments hereinafter described. Structural means and technical aspects in the embodiments described below may include ones that are replaceable and easily anticipated by those skilled in the art or substantially identical. 
     Embodiments 
       FIG. 1  is a schematic drawing of a three-dimensional object shaping apparatus according to an embodiment of this disclosure. A three-dimensional object shaping apparatus  10  illustrated in  FIG. 1  is configured to shape a three-dimensional object  5  by multilayer lamination technique. The multilayer lamination technique may refer to a method for shaping the three-dimensional object  5  by forming a plurality of layers on one another. Examples of the three-dimensional object  5  may include various structures three-dimensionally formed. The three-dimensional object shaping method carried out by the three-dimensional object shaping apparatus  10  are applicable to a method for shaping a three-dimensional object by sintering particles of a powdery material made of, for example, a metal under laser light, or a method for shaping a three-dimensional object by binding particles of a powdery material made of, for example, a resin using a binder. In such other methods, a deformation restrainer(s) may be formed in a similar manner to the three-dimensional object  5 , and a support material may be a powdery material used to form any part but the object per se. While powdery materials may fail to provide enough strength to support the three-dimensional object  5  currently shaped and the deformation restrainer, a certain kind of liquid may be used to bind particles of the powdery material in a portion that supports the object currently shaped. The liquid may be a water-soluble liquid, in which case the liquid is removed with particles of the powdery material by immersing the object in water, and the three-dimensional object  5  with the deformation restrainer connected thereto is retrieved from the water. Then, the deformation restrainer is detached from the three-dimensional object  5 , so that the three-dimensional object  5  is obtained as a final product. 
     Except for the aspects hereinafter described, the three-dimensional object shaping apparatus  10  may be configured similarly or identically to the known three-dimensional object shaping apparatuses. The three-dimensional object shaping apparatus  10  may be a partly reconfigured known inkjet printer for two-dimensional printing. For example, a known inkjet printer that uses ultraviolet-curable ink (UV ink) may be partly reconfigured and used as the three-dimensional object shaping apparatus  10 . 
     The three-dimensional object shaping apparatus  10  according to this embodiment includes an ejection unit  12 , a main scan driver  14 , an object-shaping table  16  on which the three-dimensional object  5  is formable, and a controller  20 . The ejection unit  12  ejects droplets of a material used to form the three-dimensional object  5 . The ejection unit  12  ejects, for example, droplets of a curable resin that is cured under certain conditions, and then cures the droplets to form layers constituting the three-dimensional object  5 . Specifically, the ejection unit  12  repeatedly carries out two operations multiple times; an operation to eject droplets of the curable resin as prompted by the controller  20  to form a layer, and an operation to cure the layer of the curable resin. The ejection unit  12  repeatedly carries out these operations to form a plurality of layers of the cured resin on one another. 
     The curable resin ejected from the ejection unit  12  may be an ultraviolet-curable resin that is cured under ultraviolet irradiation. In this instance, the droplets of the material ejected from the ejection unit  12  to form the three-dimensional object  5  are droplets of the ultraviolet-curable ink. The layers of the curable resin are irradiated with ultraviolet light emitted from a light source and thereby cured. The layers of the curable resin in this instance are layers of the ultraviolet-curable ink. 
     In the three-dimensional object shaping apparatus  10  according to this embodiment, the ejection unit  12  ejects ink prepared to form the three-dimensional object  5  to a working plane  18  on an upper surface of the object-shaping table  16 . The ejection unit  12  ejects droplets of ultraviolet-curable color ink to color an outer surface or an interior of the three-dimensional object  5  and obtain a colored three-dimensional object  5 . The ejection unit  12  also forms a support  6  around the three-dimensional object  5  during an operation to shape this object. The support  6  is a layered structure (support layers) that supports the three-dimensional object  5  currently shaped and is dissolved in water or the like and removed from the completed three-dimensional object  5 . 
     In this embodiment, the ejection unit  12  further forms a deformation restrainer  7 . When a modeling material is ejected and stacked in layers in the operation to shape the three-dimensional object  5 , stress may be generated, which possibly deforms the layered modeling material. During the operation to form the three-dimensional object  5 , the deformation restrainer  7  generates a force that acts against such stress-driven deformation, if any, of a deformable target portion formed of the modeling material (for example, top plate  52  described later). In this embodiment, the ejection unit  12  forms the deformation restrainer  7  using ink similar to ink containing the modeling material used to form the three-dimensional object  5 . The ejection unit  12  may form the deformation restrainer  7  using, apart from the modeling material, ink containing a material prepared to control possible deformation. In this instance, the apparatus may be further equipped with a head for ejection of the deformation restrainer material. Specific structural features and operation of the ejection unit  12  (including the formation of the deformation restrainer  7 ) will be described later in further detail. 
     The main scan driver  14  drives the ejection unit  12  to perform main scans. The main scan driver  14 , by thus driving the ejection unit  12  to perform main scans, functions as a relative movement driver that moves the ejection unit  12  and the working plane  18  relative to each other. When the ejection unit  12  is prompted to perform main scans in this embodiment, it may be inkjet heads of the ejection unit  12  that actually perform main scans. The main scan may be an operation in which the ejection unit  12  ejects the ink droplets while moving in a predetermined main scanning direction (Y direction in the drawing). 
     The main scan driver  14  has a carriage  15  and a guide rail  17 . The carriage  15  is a holder that holds the ejection unit  12  so as to face the working plane  18  of the object-shaping table  16 . The carriage  15  holds the ejection unit  12  so that the ink droplets ejected from the ejection unit  12  are directed toward the working plane  18 . In each main scan, the carriage  15  holding the ejection unit  12  moves along the guide rail  17 . The guide rail  17  is a member that guides movement of the carriage  15 . In each main scan, the guide rail  17  moves the carriage  15  as prompted by the controller  20 . 
     A movement of the ejection unit  12  in each main scan may be a relative movement to the three-dimensional object  5 . In a modified example of the three-dimensional object shaping apparatus  10 , therefore, the three-dimensional object  5  may be moved by moving the object-shaping table  16 , with the ejection unit  12  remaining unmoved at a position. 
     The object-shaping table  16  has, on its upper surface, the working plane  18 , on which the three-dimensional object  5  is shaped. The object-shaping table  16  is equipped to move its upper surface upward and downward (Z direction in the drawing), and moves the upper surface, as prompted by the controller  20 , so as to follow the progress of the three-dimensional object  5  currently shaped. Thus, a distance (interval) between the ejection unit  12  and a target surface of the three-dimensional object  5  currently shaped may be suitably adjusted. The target surface of the three-dimensional object  5  currently shaped is a surface on which a next layer is formed by the ejection unit  12 . In each main scan, the ejection unit  12  may be moved upward and downward in the Z direction, instead of the object-shaping table  16  being moved in the Z direction relative to the ejection unit  12 . 
     The three-dimensional object shaping apparatus  10  may further include any other means required to color and/or shape the three-dimensional object  5 . For example, the three-dimensional object shaping apparatus  10  may have a sub scan driver that drives the ejection unit  12  to perform sub scans. The sub scan may be an operation in which inkjet heads of the ejection unit  12  move in a sub scanning direction (X direction in the drawing) orthogonal to the main scanning direction relative to the three-dimensional object  5  currently shaped. In this instance, the sub scan driver may be a relative movement driver configured to move the ejection unit  12  and the working plane  18  relative to each other in the sub scanning direction. The sub scan driver, i.e., relative movement driver, may drive the ejection unit  12  to perform sub scans, as required, in case the three-dimensional object  5  is formed in a length in the sub scanning direction greater than an object-shaping width of the inkjet heads of the ejection unit  12 . Specifically, the sub scan driver may drive the object-shaping table  16  to move in the sub scanning direction or may drive the guide rail  17  and the carriage  15  holding the ejection unit  12  to move in the sub scanning direction, insofar as this relative movement driver is allowed to move one of the ejection unit  12  and the working plane  18  relative to the other in at least one of the main scanning direction and the sub scanning direction. 
       FIG. 2  is a drawing of a surface side of the ejection unit  12  from which the ink droplets are ejected. The ejection unit  12  has a plurality of color ink heads  32   y ,  32   m ,  32   c , and  32   k  (hereinafter, color ink heads  32   y - k ), a white ink head  36 , a clear ink head  38 , a modeling material head  34 , a support material head  40 , a plurality of ultraviolet light sources  44 , and a flattening roller unit  46 . 
     The color ink heads  32   y - k , white ink head  36 , clear ink head  38 , and modeling material head  34  are inkjet heads that eject the curable resin-containing droplets. The color ink heads  32   y - k , white ink head  36 , clear ink head  38 , and modeling material head  34  eject droplets of ultraviolet-curable inks and are arranged in the main scanning direction (Y direction) in positional alignment with one another in the sub scanning direction (X direction). 
     The color ink heads  32   y - k  eject droplets of color inks of different colors used as colorants. The color ink heads  32   y - k  are allowed to eject droplets of ultraviolet-curable color inks of yellow (Y), magenta (M), cyan (C), and black (K) used in the subtractive color mixture. The white ink head  36  ejects droplets of a white (W) ultraviolet-curable ink. Such different color inks constitute the colorants. 
     The clear ink head  38  ejects droplets of a clear-colored ultraviolet-curable ink (clear ink). The clear ink is a transparent (CL), colorless ink. The clear ink is a colorant-less ink containing an ultraviolet-curable resin. 
     The modeling material head  34  ejects droplets of an ultraviolet-curable ink used as the modeling material to shape the three-dimensional object  5 . The modeling material head  34  is allowed to eject droplets of a modeling ink (MO) having a predetermined color. While examples of the modeling ink may include the white ink and the transparent clear ink, an optional color ink may be used unless the three-dimensional object  5  is required to have an outer surface in full color. 
     The support material head  40  is an inkjet head that ejects droplets of a support material (S) used to form the support  6  (see  FIG. 1 ). The material of the support  6  may suitably be a water-soluble material that can be dissolved in water after the three-dimensional object  5  is completed. The material of the support  6  may be selected from the known materials usable to form such a support. The support material may be selected from materials by which the support  6  has a lower degree of hardness than a portion formed of the modeling material. The portion formed of the modeling material accordingly has a higher degree of hardness than a portion formed of the support material (support  6 ). 
     The color ink heads  32   y - k , white ink head  36 , clear ink head  38 , modeling material head  34 , and support material head  40  may be suitably selected from the known inkjet heads. These inkjet heads each have, on its surface facing the working plane  18  of the object-shaping table  16  (see  FIG. 1 ), a nozzle array having nozzles aligned in the sub scanning direction. The nozzle arrays of the inkjet heads are aligned in the same direction and are arranged in parallel to one another. In the main scans, these inkjet heads, while moving in the main scanning direction orthogonal to the nozzle-aligned direction, eject the ink droplets in the Z direction. 
     The ultraviolet light sources  44  radiate ultraviolet light to cure the ultraviolet-curable inks, examples of which may include ultraviolet LED (Light Emitting Diode), metal halide lamps, and mercury lamps. The ultraviolet light sources  44  are respectively disposed on one end side and the other end side of the ejection unit  12  in the main scanning direction across the color ink heads  32   y - k , white ink head  36 , clear ink head  38 , modeling material head  34 , and support material head  40 . In the three-dimensional object shaping apparatus  10  according to this embodiment, UV 1  and UV 2  are used as the ultraviolet light sources  44 . The UV 1  is disposed on one end side of the ejection unit  12  in the main scanning direction (Y direction), while UV 2  is disposed on the other end side of the ejection unit  12  in the main scanning direction (Y direction). 
     The flattening roller unit  46  is a means provided to flatten layers of the ultraviolet-curable inks formed during the operation to shape the three-dimensional object  5 . The flattening roller unit  46  is disposed between the UV 2  (ultraviolet light source  44  on the other end side of the ejection unit  12 ) and the group of the color ink heads  32   y - k , white ink head  36 , clear ink head  38 , modeling material head  34 , and support material head  40 . The flattening roller unit  46  is disposed in the main scanning direction next to the group of the color ink heads  32   y - k , white ink head  36 , clear ink head  38 , modeling material head  34 , and support material head  40 , with positions of the flattening roller unit  46  and these inkjet heads being aligned with one another in the sub scanning direction. The flattening roller unit  46  is disposed in the ejection unit  12  so as to move upward and downward relative to the ejection unit  12 . 
       FIGS. 3 and 4  are drawing of the three-dimensional object  5  formed on the working plane  18  by the ejection unit  12  and the deformation restrainer  7 .  FIG. 3  is a plan view, and  FIG. 4  is an A-A cross-sectional view of  FIG. 3 .  FIG. 5  is an enlarged view of a portion encircled with a broken line in  FIG. 4 . This embodiment is hereinafter described referring to an example in which the three-dimensional object  5  to be shaped is a model of a table  50  with four legs. 
     The table  50  has legs  51  and a top plate  52 . The legs  51  support the top plate  52 . The top plate  52  has a rectangular flat shape. The table  50  is formed, with the legs  51  and the top plate  52  being supported by the support  6 . In this embodiment, the top plate  52  is a target portion supported by the support  6 . 
     The deformation restrainer  7  includes side restrainers  71  and a bottom restrainer  72 . The side restrainers  71  each have a base  73  and connectors  74 . The bases  73  are situated on lateral sides of the top plate  52 . The base  73  has a first piece  73   a  formed along the working plane  18 , and a second piece  73   b  formed so as to intersect with the working plane  18 . The first piece  73   a  and the second piece  73   b  are bent at a bending part  73   c  and are connected to each other. In this embodiment, the first piece  73   a  is parallel to the working plane  18 , while the second piece  73   b  is perpendicular to the working plane  18 . The second piece  73   b  has a part formed along a direction intersecting with the working plane  18  and held by the support  6 . The second piece  73   b  is, therefore, restricted in upward and downward (Z direction) movements in  FIG. 4 . This structural feature may prevent that side surfaces of the top plate  52  receive impact through the connectors  74  and thereby deform upward or downward (Z direction) in  FIG. 4 . 
     The connector  74  is extending from an end of the first piece  73   a  toward a side surface  52   b  of the top plate  52  and is connected to the side surface  52   b . While the shown connectors  74  are tapered and thinner toward the side surface  52   b , there are other optional shapes of the connectors  74  described later, instead of the tapered shape. When the top plate  52  is, for example, 3 mm in thickness, a part of the connector  74  in contact with the side surface  52   b  may desirably have a width of 0.5 mm to 2 mm in cross section. However, the width may be selected from suitable values in view of factors including; number of connectors  74 , magnitude of stress causing the top plate  52  to deform, and easiness to break the top plate off at the connector  74  to detach the deformation restrainer  7  after the operation is over. As illustrated in  FIG. 5 , the top plate  52  has an inner portion  52   t  formed of, for example, white ink, and a surface portion  52   s  formed of colored inks or clear ink. The connector  74  may be formed of the same ink as used in the surface portion  52   s  of the top plate  52 , in which case the connector  74  may have the same color as the surface portion of the top plate  52 . The connector  74  may be formed of ink that differs from the ink used to form the surface portion  52   s . For example, the color inks may be used to form the surface portion  52   s , and the clear ink may be used to form the connector  74 , in which case the surface portion of the top plate  52  may be less affected in color after the connector  74  is broken off. 
     The bottom restrainer  72  has a base  75  and connectors  76 . The base  75  is situated at a position closer to the working plane  18  than the top plate  52 . The connectors  76  are protruding from a part of the base  75  facing a bottom surface  52   c  toward the bottom surface  52   c . While the shown connectors  76  may be tapered and thinner toward the bottom surface  52   c , the connectors  76  may be shaped otherwise. The connector  76  may be formed of the same ink as used in the surface portion  52   s  of the top plate  52 . The connector  76  may be formed of any ink but the ink used to form the surface portion  52   s.    
     The controller  20  controls the structural elements of the three-dimensional object shaping apparatus  10 , for example, controls the operations of the ejection unit  12  and the main scan driver  14 . The controller  20  has a CPU (Central Processing Unit) for executing various processes, RAM (Random Access Memory) as a storage for various pieces of information, and ROM (Read Only Memory). The controller  20  controls the structural elements of the three-dimensional object shaping apparatus  10  to form the three-dimensional object  5  desirably obtained based on shape-related information and color image-related information of the three-dimensional object  5 . 
       FIG. 6  is a functional block diagram of the controller  20 . As illustrated in  FIG. 6 , the controller  20  includes an input unit  21 , an output unit  22 , a processor  23 , a storage  24 , and a bus line  25  that interconnects these devices. The input unit  21  receives data inputted from an external apparatus such as a personal computer, not illustrated in the drawing. The output unit  22  outputs control signals operable to control of an object-shaping operation. 
     The processor  23  has a drive controller  26 , a head controller  27 , and a deformation restrainer controller  28 . The drive controller  26  controls movements of the ejection unit  12  and the object-shaping table  16 . The head controller  27  controls the operation to eject inks from the color ink heads  32   y  to  32   k , white ink head  36 , clear ink head  38 , modeling material head  34 , and support material head  40 , and also controls the operations of the ultraviolet light sources  44  and the flattening roller unit  46 . 
     The deformation restrainer controller  28  controls the operation to form the deformation restrainer  7 . In response to receipt of three-dimensional data indicating the shape of the three-dimensional object  5  to be obtained inputted, for example, from the input unit  21 , the deformation restrainer controller  28  determines based on the inputted three-dimensional data whether a predetermined target portion is formable with the modeling material in the object-shaping operation. The target portion may include any portion deformable under stress, such as a flat portion, a linear portion, or a bar-shaped portion. The target portion is not necessarily limited to any part of the completed three-dimensional object  5  but includes any portion temporarily formed during the object-shaping operation. When it is determined that the target portion is formable, the deformation restrainer controller  28  forms the deformation restrainer  7  in addition to the three-dimensional object  5 . The deformation restrainer controller  28  decides and sets a position and shape of the deformation restrainer  7  depending on a shape of the target portion to be formed. The deformation restrainer  7  may be provided irrespective of any shape of the target portion, for example, whether the target portion has an inclined, curved, or spherical surface, or has a linear or curved part. In case the target portion has any shape that may be subject to a greater deformation-causing stress, for example, large, thin, and flat target shape, the deformation restrainer controller  28  may connect the deformation restrainer  7  to a lower end side of the target portion in a layer-stacking direction. This may ensure that possible deformation of the target portion is prevented in an early stage of the object shaping step. The shape of the deformation restrainer  7  may be selected from data of a plurality of finite shapes previously stored in the storage  24  described later, or may be decided and set based on a signal externally inputted by an operator. The shape of the deformation restrainer  7  may be selected from various shapes including circular, polygonal, curved, and bent shapes. The deformation restrainer controller  28  transmits data set for the position and shape of the deformation restrainer  7  to the head controller  27 . The deformation restrainer controller  28  may be installed in an external apparatus or may be prepared and set when shape-related data is generated. 
     In the storage  24  are stored programs and data associated with the object-shaping operation of the three-dimensional object shaping apparatus  10 . The storage  24  has a shape-related data storage  29 . The shape-related data storage  29  is used to store shape-related data of the deformation restrainer  7 . 
     Next, the operation of the three-dimensional object shaping apparatus  10  is hereinafter described.  FIG. 7  is a flow chart of the operation carried out by the three-dimensional object shaping apparatus  10 .  FIGS. 8 to 10  are drawings that each illustrate a stage in the operation carried out by the three-dimensional object shaping apparatus  10 . In Step S 10 , three-dimensional data of the three-dimensional object  5  from an external apparatus is inputted to the controller  20 , as illustrated in  FIG. 7 . Based on the inputted three-dimensional data of the three-dimensional object  5 , the deformation restrainer controller  28  determines whether a predetermined target portion is formable with the modeling material in the object-shaping operation (Step S 20 ). 
     When it is determined that the target portion is formable (Yes in Step S 20 ), the deformation restrainer controller  28  forms the deformation restrainer  7  in addition to the three-dimensional object  5 . The deformation restrainer controller  28  decides and sets the position and shape of the deformation restrainer  7  depending on the shape of the target portion (Step S 30 ). The deformation restrainer controller  28  transmits data set for the position and shape of the deformation restrainer  7  to the head controller  27 . 
     The head controller  27  that received the set data from the deformation restrainer controller  28  controls the operations of the heads, ultraviolet light sources  44 , and flattening roller unit  46  based on the received data, and forms the three-dimensional object  5  and the deformation restrainer  7  (Step S 40 ). In Step S 40 , the controller  20  prompts a three-dimensional object shaping step S 41  to be carried out, in which the modeling material constituting the table  50  (three-dimensional object  5 ) and the support material that supports the three-dimensional object are ejected in layers to the working plane  18 . 
     In the three-dimensional object shaping step S 41 , based on the three-dimensional data received from an external apparatus, the drive controller  26  drives the main scan driver  14  and the object-shaping table  16  to operate, and the head controller  27  controls the operation to eject inks from the ejection unit  12 . As a result, a modeling material Q 1  and a support material Q 2  ejected from the ejection unit  12  are layered in a shape as indicated by the three-dimensional data on the working plane  18  of the object-shaping table  16 , as illustrated in  FIG. 8 . 
     The controller  20  further prompts a deformation restrainer shaping step S 42  to be carried out, in which the deformation restrainer  7  is formed. In the deformation restrainer shaping step S 42 , based on the set data from the deformation restrainer controller  28 , the drive controller  26  drives the main scan driver  14  and the object-shaping table  16  to operate, and the head controller  27  controls the operation to eject inks from the ejection unit  12 . As a result, a deformation restrainer material Q 3  constituting the deformation restrainer  7  is ejected to and layered at a position in a shape as indicated by design data, as illustrated in  FIG. 9 . In this embodiment, the deformation restrainer material Q 3  and the modeling material Q 1  are the same material. Thus, Step S 40  includes the deformation restrainer shaping step S 42  of forming the deformation restrainer  7  and the three-dimensional object shaping step S 41  of forming the three-dimensional object. When the modeling material Q 1  and the support material Q 2  are ejected from the ejection unit  12  in a main scan, the deformation restrainer material Q 3  is ejected as well in the same main scan. 
     As a result of the three-dimensional object shaping step S 41  and the deformation restrainer shaping step S 42 , the three-dimensional object  5  (the table  50  having the legs  51  and the top plate  52 ) is formed on the working plane  18  of the object-shaping table  16 , as illustrated in  FIG. 10 . The table  50  is supported by the support material Q 2 . In  FIG. 10 , the top plate  52  is supported by the support material Q 2  and has its upper surface  52   a  left exposed. In this embodiment, the portion formed of the modeling material Q 1  has a higher degree of hardness than the support  6  formed of the support material Q 2 . The top plate  52 , which is the target portion, is harder than the support  6  made of the layers of the support material Q 2 . 
     Within the support material Q 2 , the deformation restrainer  7  is formed that includes the side restrainers  71  connected to the side surfaces  52   b  of the top plate  52  and the bottom restrainer  72  connected to the bottom surface  52   c  of the top plate  52 . The side restrainers  71  are situated on lateral sides of the top plate  52  of the table  50 . In the deformation restrainer shaping step S 42 , the deformation restrainer  7  is formed on the support material Q 2  on the working plane  18 . The deformation restrainer  7  is formed away from the working plane  18 , i.e., without any contact with the working plane  18 , as illustrated in  FIG. 10 . The deformation restrainer  7  is formed in contact in at least a part thereof with the support material Q 2 . The side restrainers  71  of the deformation restrainer  7  illustrated in  FIG. 10  are each in contact with the support material Q 2  in the whole surface of the base  73  (first piece  73   a , second piece  73   b , bending part  73   c ). The bottom restrainer  72  is in contact with the support material Q 2  in the whole surface of the base  75 . When the side restrainers  71  and the bottom restrainer  72  are subject to stress causing deformation in the X direction, Y direction, Z direction, θX direction, θY direction, and/or θZ direction, the support  6  in contact with the side restrainers  71  and the bottom restrainer  72  immobilizes these restrainers, acting against such stress-driven deformation. The cross section of the connector  74  may be suitably adjusted depending on the magnitude of stress acting on the top plate  52  which is the target portion. 
     When deformation of the top plate  52  (target portion) formed of the modeling material Q 1 , is possibly occurring, the side restrainers  71  and the bottom restrainer  72  are subject to stress causing the deformation. The side restrainers  71  and the bottom restrainer  72 , under the stress, are subject to at least one of a frictional force or a pressure from the support  6 . This frictional force and/or pressure is a force that acts against the stress-driven deformation. 
     In this embodiment, the deformation restrainer  7  is formed of the modeling material Q 1 . A portion formed of the modeling material Q 1  has a higher degree of hardness than the support  6  formed of the support material Q 2 . The deformation restrainer  7  is, therefore, harder than the support  6  which is the layered structure of the support material Q 2 . Thus, unwanted penetration may be prevented when deformation of the top plate  52  (target portion) occurs. 
     Step S 40  includes a removing step S 43  of removing the deformation restrainer  7  connected to the top plate  52  after the table  50  (three-dimensional object  5 ) formed of the modeling material Q 1  is obtained and the support material Q 2  is removed. In the removing step S 43 , the deformation restrainer  7  may be easily removed by cutting or bending its part connected to the top plate  52  (for example, connectors  74 ). A nipper or a cutter may be used as a cutting means. Part of the top plate  52  from which the deformation restrainer  7  has been removed is then subjected to a surface treatment such as polishing. As a result, the table  50  is obtained as a final product. 
     When the deformation restrainer controller  28  determines in Step S 20  that the flat, linear, or bar-shaped target portion is not formable (No in Step S 20 ), the head controller  27  prompts the object-shaping operation to be carried out without the deformation restrainer  7  being formed (Step S 50 ). In Step S 50 , the head controller  27  controls the operation as in the three-dimensional object shaping step S 41  of Step S 40 . 
     Subsequent to Step S 40  or Step S 50 , the controller  20  stops the operations of the respective structural elements to finish the object-shaping operation when an operation-end signal outputted from a program or inputted from an external apparatus is detected. 
       FIG. 11  is a drawing of an exemplified deformation of a table  150  according to a comparative example.  FIG. 11  illustrates the table  150  currently formed in an equal shape and dimension to the table  50 , in which no deformation restrainer  7  is formed. In the table  150  currently formed, the modeling material Q 1  of a top plate  152  constitutes a flat shape on the support material Q 2 , as illustrated in  FIG. 11 . In this stage, the top plate  152  may possibly detach from the support material Q 2  under stress and deform toward the ejection unit  12 . Specifically, the top plate  152  may possibly deform as illustrated with  152   a  or  152   b  in  FIG. 11 . A deformation  152   a  indicates that a portion at the center of the top plate  152  is deformed away from the support material Q 2 . A deformation  152   b  indicates that end parts of the top plate  152  are deformed away from the support material Q 2 . Such deformation is not necessarily limited to the top plate  152  formed on the support material Q 2 . The top plate  152  directly formed on the working plane  18  may similarly deform toward the ejection unit  12 . Such deformation of the top plate  152  toward the ejection unit  12  may cause the three-dimensional object  5  to degrade in quality or cause the three-dimensional object  5  to be poorly shaped in case any deformed part contacts the ejection unit  12 . 
     To address such an issue, the three-dimensional object shaping method according to this embodiment is a method for shaping the three-dimensional object  5  on the working plane  18 , including: the three-dimensional object shaping step S 41  of stacking the modeling material Q 1  and the support material Q 2  in layers on the working plane  18 , the modeling material Q 1  constituting the three-dimensional object  5 , the support material Q 2  serving to support the modeling material Q 1 ; and the deformation restrainer shaping step S 42  of forming the deformation restrainer  7  away from the working plane  18  and in contact in at least a part thereof with the support material Q 2 , the deformation restrainer  7  being a portion distinct from the top plate  52  (target portion) formed of the modeling material Q 1  in the three-dimensional object shaping step S 41  and serving to generate a force that acts against stress causing the top plate  52  to deform. 
     According to this embodiment, the deformation restrainer  7  may serve to generate a force that acts against such stress-driven deformation, if any, of the top plate  52  which is the target portion. This may suppress the risk of the top plate  52  being deformed. Because the deformation restrainer  7  at least partly stays in contact with the support material Q 2 , the contact with the support material Q 2  may ensure that a force is generated against possible deformation of the top plate  52 . Further, the deformation restrainer  7  formed in contact with the three-dimensional object  5  may suppress the risk of possible deformation of the top plate  52  (target portion) regardless of any shape of the three-dimensional object  5 . In the three-dimensional object shaping method for shaping the three-dimensional object  5  on the working plane  18 , the three-dimensional object shaping step S 41  may be a step of shaping the three-dimensional object  5  by stacking a powdery material in layers on the working plane  18  and repeatedly irradiating the layers with laser light appropriate for shape-related data. In this instance, the deformation restrainer shaping step S 42  may be a step of forming, simultaneously with the formation of the three-dimensional object  5 , the deformation restrainer  7  in contact in at least a part thereof with the three-dimensional object  5 , the deformation restrainer  7  being a portion distinct from the top plate  52  (target portion) of the three-dimensional object  5  formed in the three-dimensional object shaping step and serving to generate a force that acts against stress causing the top plate  52  to deform. The three-dimensional object shaping step S 41  may be a step of forming the three-dimensional object  5  by stacking a powdery material in layers on the working plane  18  and ejecting a binder material appropriate for the shape-related data to the powdery material. In this instance, the deformation restrainer shaping step S 42  may be a step of forming, simultaneously with the formation of the three-dimensional object  5 , the deformation restrainer  7  in contact in at least a part thereof with the three-dimensional object  5 , the deformation restrainer  7  being a portion distinct from the top plate  52  (target portion) of the three-dimensional object  5  formed in the three-dimensional object shaping step and serving to generate a force that acts against stress causing the top plate  52  to deform. 
     In the three-dimensional object shaping method according to this embodiment, the deformation restrainer shaping step S 42  may form the connectors  74  that allows the deformation restrainer  7  to connect in at least a part thereof to the top plate  52  which is the target portion. This may allow the deformation restrainer  7  to receive, through the connector  74 , stress possibly causing the top plate  52  to deform and thus further ensures that a force is generated against such deformation-causing stress. 
     In the three-dimensional object shaping method according to this embodiment, the deformation restrainer shaping step S 42  may form the bases  73 ,  75  of the deformation restrainer  7  on the opposite side of the top plate  52  across the connectors  74 , so that the connectors  74  are tapered and thinner toward the top plate  52 . According to this configuration, the connector  74  has a part progressively thinner toward the top plate  52 . After the object is completed, therefore, the thinned part may facilitate removal of the deformation restrainer that is no longer necessary. 
     The three-dimensional object shaping method according to this embodiment may further include the removing step S 43  of removing the deformation restrainer  7  connected to the top plate  52  from the three-dimensional object  5  after the object  5  formed of the modeling material Q 1  is completed and the support material Q 2  is removed. According to this configuration, the three-dimensional object  5  may be readily obtained by removing the deformation restrainer  7  after the support material Q 2  is removed from the completed three-dimensional object  5 . 
     In the three-dimensional object shaping method according to this embodiment, the deformation restrainer shaping step S 42  may form the deformation restrainer  7  in a shape having the second piece  73   b  formed along a direction intersecting with the working plane  18 . According to this configuration, the deformation restrainer  7  having the second piece  73   b  formed along a direction intersecting with the working plane  18  may be prevented from extending along the working plane  18 . As a result, the support material Q 2  used may be economized. 
     In the three-dimensional object shaping method according to this embodiment, the deformation restrainer shaping step S 42  may form the deformation restrainer  7  in a shape having a flat portion parallel to the working plane  18 . According to this configuration, the flat portion may enhance the contact with the support material Q 2  and thereby ensure that a force is generated against possible deformation of the top plate  52 . 
     In the three-dimensional object shaping method according to this embodiment, the deformation restrainer shaping step S 42  may form at least two deformation restrainers  7  in a direction intersecting with the working plane  18 . One of the two deformation restrainers  7  closer to the working plane  18  may have a shape with a flat portion parallel to the working plane  18 , while the other one of the two deformation restrainers  7  farther from the working plane  18  may have a shape with a portion formed along a direction intersecting with the working plane  18 . By thus having at least two deformation restrainers  7 , the deformation restrainers  7  may be prevented from extending along the working plane  18 , and a force may be surely generated against possible deformation of the top plate  52 . 
     In the three-dimensional object shaping method according to this embodiment, the deformation restrainer shaping step S 42  may form the deformation restrainer  7  using the modeling material Q 1 . Using the modeling material Q 1  to form the deformation restrainer  7  may save additional labor of preparing a dedicated material for the deformation restrainer  7 . 
     In the three-dimensional object shaping method according to this embodiment, the deformation restrainer  7  may have a higher degree of hardness than layers of the support material Q 2 . According to this configuration, unwanted penetration may be prevented when deformation of the deformation restrainer  7  occurs. 
     In the three-dimensional object shaping method according to this embodiment, the top plate  52  may have a higher degree of hardness than layers of the support material Q 2 . While the top plate  52 , if deformed, is possibly detached from the support material, the top plate  52  harder than layers of the support material Q 2  may be unlikely to detach from the support material Q 2 . 
     The three-dimensional object shaping apparatus  100  according to this embodiment is an apparatus that forms the three-dimensional object  5  on the working plane  18 , including: the ejection unit  12  that stacks the modeling material Q 1 , the support material Q 2 , and the deformation restrainer material Q 3  in layers on the working plane  18 , the modeling material Q 1  constituting the three-dimensional object  5 , the support material Q 2  serving to support the modeling material Q 1 , the deformation restrainer material Q 3  constituting the deformation restrainer  7  being a portion distinct from top plate  52  (target portion) formed of the modeling material Q 1  and serving to generate a force that acts against stress causing the top plate  52  to deform; and the controller  20  that prompts the ejection unit  12  to form, apart from the three-dimensional object  5 , the deformation restrainer  7  away from the working plane  18  and in contact in at least a part thereof with the support material Q 2  at the time of the top plate  52  (target portion) being formed. 
     According to this configuration, a force that acts against stress causing the top plate  52  (target portion) to deform may be effectively generated. The risk of the top plate  52  being deformed may be accordingly reduced, and the object-shaping operation may be smoothly performed. The three-dimensional object shaping apparatus  100  may be equipped with, in place of the ejection unit  12 , an object-shaping unit that stacks a powdery material in layers on the working plane  18  and irradiates the layers with laser light appropriate for shape-related data so as to form the three-dimensional object  5  and the deformation restrainer  7 , the deformation restrainer  7  being a portion distinct from the top plate  52  (target portion) of the three-dimensional object  5  and serving to generate a force that acts against stress causing the top plate  52  to deform. The three-dimensional object shaping apparatus  100  may be equipped with, in place of the ejection unit  12 , an object-shaping unit that stacks a powdery material in layers on the working plane  18  and ejects a binder material appropriate for shape-related data to the powdery material so as to form the three-dimensional object  5  and the deformation restrainer  7  distinct from the top plate  52  (target portion) of the three-dimensional object  5  and serving to generate a force that acts against stress causing the top plate  52  to deform. When the top plate  52  is formed by the apparatus thus configured, the controller  20  may prompt the object-shaping unit to form, simultaneously with the formation of the three-dimensional object, the deformation restrainer  7  in contact in at least a part thereof with the three-dimensional object  5 . 
     The technical scope of this disclosure includes but is not necessarily limited to the embodiment described thus far. Any modifications within the scope and spirit of this disclosure may be acceptable. For example, the target portion of the three-dimensional object described in the embodiment is the flat top plate  52  of the table  50 , however, is not necessarily limited thereto.  FIG. 12  is a drawing of a modified example of the three-dimensional object  5  formed on the working plane  18  and the deformation restrainer  7 . In the example illustrated in  FIG. 12 , the three-dimensional object  5  is a C-shaped member  55  having a bottom plate  55   a  and side plates  55   b  and  55   c.    
     In the C-shaped member  55 , the bottom restrainer  72  (deformation restrainer  7 ) is connected to the bottom plate  55   a  of the C-shaped member  55 . The side restrainers  75  (deformation restrainer  7 ) are connected to the side plates  55   b  and  55   c . The side restrainers  75  are set in a region between the side plates  55   b  and  55   c , i.e., in the hollowed inside of the C-shaped member  55 . The support material layered on an outside of the side plates  55   b  and  55   c  may be reduced as compared with having the side restrainers  75  connected to the side plates  55   b  and  55   c  from an outside of the hollowed inside of the C-shaped member  55 . When the C-shaped member  55  is positioned without its hollowed inside been seen, removal of the deformation restrainer  7  may be unnecessary, in which case the removing step may be skipped. 
       FIG. 13  is a drawing of a modified example of the three-dimensional object  5  formed on the working plane  18  and the deformation restrainer  7 . In the example illustrated in  FIG. 13 , the three-dimensional object  5  is a block-shaped member  56 . When the block-shaped member  56  is formed, a modeling material prepared for this member is stacked in layers vertically upward on the support material. During the formation of the block-shaped member, the modeling material layered in a flat shape on the support material may possibly deform and detach from the support material. In the example of  FIG. 13 , when a three-dimensional object desirably obtained has no flat portion in its final shape, the deformation restrainer  7  is connected to the three-dimensional object  5  insofar as such a flat portion is formed on the support material during the operation to form this object. While the side restrainers  79  are connected, as the deformation restrainer  7 , to the side surfaces of the block-shaped member  56  in  FIG. 13 , a bottom restrainer may instead be connected to a bottom surface of the block-shaped member  56 . 
       FIG. 14  is a drawing of a modified example of the three-dimensional object  5  formed on the working plane  18  and the deformation restrainer  7 . In the example illustrated in  FIG. 14 , the three-dimensional object  5  is a member  57  having plate-shaped portions  57   a  and  57   b  that are spaced apart in the layer-stacking direction. In the member  57  thus shaped, the modeling material is layered in a flat shape on the support material at different times. At the time of the plate-shaped portions  57   a  and  57   b  being formed, therefore, the side restrainers  77  (deformation restrainer  7 ) are connected to side surfaces of the plate-shaped portions  57   a  and  57   b.    
     After the plate-shaped portion  57   a  is formed, a floating restrainer  78  may be formed as the deformation restrainer  7  between and away from the plate-shaped portions  57   a  and  57   b . In this structural option, a force that acts against deformation-causing stress may be acted upon the plate-shaped portion  57   a  when one end of the plate-shaped portion  57   a  on +Y side deforms toward +Z side. Likewise, a force that acts against deformation-causing stress may be acted upon the plate-shaped portion  57   b  when one end of the plate-shaped portion  57   b  on +Y side deforms toward −Z side. Thus, the deformation restrainer  7  is not necessarily connected to the target portion per se insofar as the target portion formed of the modeling material can be subject to a force that acts against deformation-causing stress. By not having the deformation restrainer  7  connected to the target portion, removal of the deformation restrainer  7  from the three-dimensional object  5  becomes unnecessary after the support  6  is removed. 
       FIGS. 15 to 18  are drawings of other examples of the deformation restrainer  7 . Suitable one of these examples may be selected depending on the shape of the three-dimensional object  5 , direction of deformation, degree of deformation, and position at which and direction in which the deformation restrainer  7  is attachable. A deformation restrainer  81  illustrated in  FIG. 15  includes a base  81   a  having a flat rectangular shape and connectors  81   b  having a truncated conical shape. The two connectors  81   b  are arranged next to each other on side surfaces of the base  81   a , however, the connectors  81   b  may be arranged otherwise. 
     A deformation restrainer  82  illustrated in  FIG. 16  includes a base  82   a  having a flat rectangular shape and connectors  82   b  having a truncated conical shape. The four connectors  82   b  are arranged next to one another on a surface of the base  82   a , however, the connectors  82   b  may be arranged otherwise. 
     A deformation restrainer  83  illustrated in  FIG. 17  has a first base  83   a  having a flat rectangular shape, a protrusion  83   b  protruding from the first base  83   a , and a connector  83   c . This deformation restrainer may be suitable for a narrow, thin, or curved structure or object. The protrusion  83   b  is disposed at a position at the center of the first base  83   a  in its longitudinal direction. The connector  83   c  is disposed at a protruding edge of the protrusion  83   b . Positions, shapes or the like of the protrusion  83   b  and the connector  83   c , however, may be decided otherwise. 
     A deformation restrainer  84  illustrated in  FIG. 18  has a base  84   a  with a dented part  84   b , and connectors  84   c . This deformation restrainer is suitable for deformation caused by greater stress. The dented part  84   b  in the base  84   a  and the connectors  84   c  linearly extending may allow for a greater area of contact with the support material and a greater area in total of the connectors  84   c . This may ensure that a greater force is acted against stress causing the target portion to deform. 
       FIG. 19  is a drawing that illustrates an example of the deformation restrainer  7 . In the example illustrated in  FIG. 19 , a deformation restrainer  85  has a base  85   a  and a connector  85   b . The base  85   a  is formed so that its whole lower surface is allowed to contact the working plane  18 . The lower surface of the base  85   a  may at least partly contact the working plane  18 , instead of the whole lower surface making contact with the working plane  18 . The base  85   a  can be formed by directly ejecting ink to the working plane  18 . The connector  85   b  may be extending from the base  85   a  toward the block-shaped member  56 , and an edge of the connector  85   b  is connected to the three-dimensional object  5 . Thus, the base  85   a  of the deformation restrainer  85  is in contact with the working plane  18 . A force that acts against any deformation-causing stress, therefore, may be more stably and reliably generated. While the block-shaped member  56  is formed as the three-dimensional object  5  in the example illustrated in  FIG. 19 , the description given so far may be applicable to the three-dimensional object  5  having other shapes. 
       FIG. 20  is a drawing that illustrates an example of the deformation restrainer  7 . In the example illustrated in  FIG. 20 , the deformation restrainer  7  includes deformation restrainers  86 ,  87 , and  88  arranged below a flat member  58 . The deformation restrainer  86  is set at a position below the center of the flat member  58 . The deformation restrainer  87  is set at a position below one end of the flat member  58  (left end in  FIG. 20 ). The deformation restrainer  88  is set at a position below the other end of the flat member  58  (right end in  FIG. 20 ). 
     The deformation restrainer  86  has a base  86   a , a protrusion  86   b , and a connector  86   c . The base  86   a  is formed so that its whole lower surface is allowed to contact the working plane  18 . The protrusion  86   b  is extending upward toward the flat member  58  from the center of the base  86   a . The connector  86   c  is connected to a lower surface of the flat member  58 . The deformation restrainer  87  has a base  87   a , a protrusion  87   b , and a connector  87   c . The base  87   a  is formed so that its whole lower surface is allowed to contact the working plane  18 . The protrusion  87   b  is extending upward toward the flat member  58  from one end (left end in  FIG. 20 ) of the base  87   a . The connector  87   c  is connected to the lower surface of the flat member  58 . The deformation restrainer  88  has a base  88   a , a protrusion  88   b , and a connector  88   c . The base  88   a  is formed so that its whole lower surface is allowed to contact the working plane  18 . The protrusion  88   b  is extending upward toward the flat member  58  from the other end (right end in  FIG. 20 ) of the base  88   a . The connector  88   c  is connected to the lower surface of the flat member  58 . 
     Thus, the bases  86   a ,  87   a , and  88   a  of the deformation restrainers  86 ,  87 , and  88  are in contact with the working plane  18 . A force that acts against any deformation-causing stress, therefore, may be even more stably and reliably generated. The lower surfaces of the bases  86   a ,  87   a , and  88   a  may at least partly contact the working plane  18 , instead of the whole lower surfaces making contact with the working plane  18 . The bases  86   a ,  87   a , and  88   a  can be formed by directly ejecting ink to the working plane  18 . The shapes of the deformation restrainers  85 ,  86 ,  87 , and  88  may be decided and set depending on the shape of the three-dimensional object  5 , or may be selected from pre-stored shapes. 
       FIGS. 21 to 23  are drawings of examples of the three-dimensional object shaping method. As illustrated in  FIG. 21 , the support  6  is formed on the working plane  18 , and a base  89   a  and a connector  89   b  of a deformation restrainer  89  are formed on the support  6 . The base  89   a  may be formed so that its lateral direction in  FIG. 21  is coincident with the longitudinal direction. The base  89   a  has a longitudinal dimension d 1  that can be set to a suitable value in accordance with dimensions of the three-dimensional object. 
     Longitudinal both ends of the base  89   a  may possibly warp and detach from the support  6  depending on the longitudinal dimension d 1 , as illustrated in  FIG. 22 , while a portion of the base  89   a  including its longitudinal center part is in contact with the support  6 . A dimension of the portion of the base  89   a  in contact with the support  6  may be set to d 2  smaller than d 1 . While  FIG. 22  illustrates possible warp of the longitudinal both ends of the base  89   a , the description given so far and below may be applicable to warp of a portion at the center of the base  89   a  in the longitudinal direction. 
     As described earlier, ends of the base  89   a  in the deformation restrainer  89  formed on the support  6  may detach and warp away from the support material  6 . To avoid that, a deformation restrainer  90  is formed on the support  6 , as illustrated in  FIG. 23 . The deformation restrainer  90  has a base  90   a  smaller than the dimension d 1  in a planar direction in which ends of the base  89   a  are detachable (longitudinal direction in this example). In this instance, d 2  may be a dimension of the deformation restrainer  90  corresponding to the longitudinal direction of the deformation restrainer  89 . The dimension is not necessarily limited to d 2  and may be set to any value that allows to prevent ends of the base  90   a  from warping. 
     In case ends of the base  89   a  formed on the support  6  warp away from the support  6 , the base  90   a  shorter in an end-warping direction may be formed instead. The ends of the base  90   a  longitudinally shorter may be unlikely to warp away from the support  6 . 
     It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed embodiments without departing from the scope or spirit of the disclosure. In view of the foregoing, it is intended that the disclosure covers modifications and variations provided that they fall within the scope of the following claims and their equivalents.