Method and apparatus for forming three-dimensional laminated product from photo-curable liquid

Abstract

A three-dimensional laminated product forming apparatus and method for forming a three-dimensional laminated product from a photo-curable liquid by progressively superposing solid laminae one on top of another by photo-curing a surface layer of the photo-curable liquid and converting it to a solid lamina. A product table is provided on which a three-dimensional solid product is built up in progressive steps and which is incrementally advanced into the photo-curable liquid by a specified depth each step. A liquid surface leveling device works as a capillary to draw up a photo-curable liquid by capillary action while it is in contact with the surface of the photo-curable liquid contained in the container. The device is moved over the surface of the photo-curable liquid to apply the collected photo-curable liquid over a three-dimensional laminated product being partly built up on a product table to form a uniform thickness of a surface layer of the photo-curable liquid with a surface leveled and smoothed over the three-dimensional laminated product being partly built up. An irradiating head forms a beam spot of reactive stimulation on the surface to cure the surface layer and convert it to a solid lamina on the three-dimensional laminated product being partly built up as the three-dimensional laminated product.

What is claimed is:  
     
         1 . A three-dimensional laminated product forming apparatus for forming a three-dimensional laminated product from a photo-curable liquid by progressively superposing solid laminae having a specified thickness one on top of another, each said solid lamina being provided by photo-curing a surface layer of the photo-curable liquid, said three-dimensional laminated product forming apparatus comprising: 
 a container for holding a photo-curable liquid;    a product table on which a three-dimensional laminated product is built up in progressive steps, said product table being positioned in said photo-curable liquid and adapted to be incrementally advanced into the container step by step, each step being a equal to a specified thickness for each solid lamina;    a liquid surface leveling device defining a working gap adapted to draw photo-curable liquid into the device by capillary action to create a reserve of photo-curable therein, said liquid surface leveling device being movable horizontally in the container to pass over a surface of photo-curable liquid when held in said container to form a smoothed and leveled surface layer of photo-curable liquid over a three-dimensional laminated product that is being built up on the product table; and    an irradiating head for forming a beam spot of reactive stimulation in the container that corresponds to the smoothed and leveled surface layer of photo-curable liquid at the specified level so as thereby to cure and convert the smoothed and leveled surface layer as a solid lamina on the three-dimensional laminated product being built up on said product table.    
     
     
         2 . A three-dimensional solid product forming apparatus as defined in    claim 1   , wherein said liquid surface leveling device includes at least one blade defining the gap for drawing the photo-curable liquid by capillary action into a cavity defined by the at least one blade.  
     
     
         3 . A three-dimensional solid product forming apparatus as defined in    claim 2   , wherein said blade is made of a porous material.  
     
     
         4 . A three-dimensional solid product forming apparatus as defined in    claim 2   , wherein said blade is formed with a plurality of gaps, each defining a cavity for drawing photo-curable liquid into each cavity by capillary action.  
     
     
         5 . A three-dimensional solid product forming apparatus as defined in    claim 2   , wherein said blade is shaped with vertical depending portions that partly lie below the surface of photo-curable liquid held in the container when said product table advances incrementally into said container during the formation of the laminated product.  
     
     
         6 . A three-dimensional solid product forming apparatus as defined in    claim 1   , wherein said liquid surface leveling device comprises at least two blades arranged face to face to define therebetween a narrow gap through which the photo-curable liquid is drawn by capillary action.  
     
     
         7 . A three-dimensional solid product forming apparatus as defined in    claim 6   , wherein each said blade is made of a porous material.  
     
     
         8 . A three-dimensional solid product forming apparatus as defined in    claim 6   , wherein each said blade is formed with a number of holes.  
     
     
         9 . A three-dimensional solid product forming apparatus as defined in    claim 6   , wherein said liquid surface leveling device further comprises a porous member interposed between said blades above the gap to absorb photo-curable liquid.  
     
     
         10 . A three-dimensional solid product forming apparatus as defined in    claim 6   , wherein at least one of said blades is shaped to partly depend vertically to be situated below a surface of photo-curable liquid when said product table is advance into the photo-curable liquid by said distance equal to said specified thickness of a solid lamina.  
     
     
         11 . A method for forming a three-dimensional laminated product from a photo-curable liquid by progressively superposing solid laminae having a specified thickness one on top of another, each said solid lamina being provided by photo-curing a surface layer of the photo-curable liquid, said method comprising the steps of: 
 filling a container with a photo-curable liquid to define a working surface;    advancing a product table, on which a three-dimensional laminated product is built up in progressive steps, into said photo-curable liquid incrementally step by step with each step being a depth equal to said specified thickness of said solid lamina;    drawing photo-curable liquid by capillary action into a reservoir defined in a liquid surface leveling device;    moving the liquid surface leveling device over the working surface of said photo-curable liquid in said container to coat and smooth said photo-curable liquid over a three-dimensional laminated product that is being built up on said product table; and    irradiating a beam spot of reactive stimulation on said smoothed and leveled surface layer of said photo-curable liquid at said working surface to cure and convert said smoothed and leveled surface layer as a solid lamina on said three-dimensional laminated product being built up on said product table.    
     
     
         12 . A method as defined in    claim 11   , wherein the reservoir in said liquid surface leveling device includes at least a blade.  
     
     
         13 . A method as defined in    claim 12   , wherein said blade is made of a porous material.  
     
     
         14 . A method as defined in    claim 12   , wherein said blade is formed with a number of holes.  
     
     
         15 . A method as defined in    claim 2   , including the step of sinking portions of said blade below the working surface of said photo-curable liquid when said product table is incrementally advance into said photo-curable liquid by said distance equal to said specified thickness of said solid lamina.  
     
     
         16 . A method as defined in    claim 11    wherein the irradiation is effected by a He—Cd laser having a wavelength of about 325 nm.  
     
     
         17 . A method as defined in    claim 11    including the further step of removing the three dimensional laminated product from the photo-curable liquid of the container, washing the removed product, and subjecting the washed product to a secondary hardening by irradiating with ultraviolet radiation.  
     
     
         18 . A method as defined in    claim 11    wherein only the portions of the working surface are irradiated which correspond to the perimeter of the three dimensional laminated product being built during the formation of each lamina, and the entire portion of the working surface corresponding to the entire cross-section of the three dimensional laminated product is irradiated for the first and last lamina and for each successive X lamina, where X is a whole integer between 6 and 10.  
     
     
         19 . A method as defined in    claim 11   , including the further step of absorbing the photo-curable liquid in the reservoir into a porous body.  
     
     
         20 . A method as defined in    claim 11    wherein the entrance to the reservoir is set at approximately 1.