Patent Publication Number: US-2021170672-A1

Title: Three-dimensional printer

Description:
TECHNICAL FIELD 
     The present invention relates to a three-dimensional printer and more specifically, to a three-dimensional printer capable of piling various materials having various colors. 
     DESCRIPTION OF THE RELATED ART 
     A three-dimensional printer is a device for manufacturing a physical 3D object on the basis of a three-dimensional design made through a computer program. Three-dimensional printing largely falls into three categories depending on materials used for 3D printing. First, fused deposition modeling (FDM) is a technology where solid filaments are used as a raw material. Second, digital light processing (DLP) is a technology where liquid materials are used as a raw material. Finally, selective laser sintering (SLS) is a technology where powdered materials are used as a raw material. 
     In recent years, a DLP-type 3D printer has been most widely used to produce micro forms. In the case of a DLP-type 3D printer, ultra ray (UV) curable resins that are cured with ultraviolet light are used as a raw material. In general, such a DLP-type 3D printer includes a resin storing part that stores UV curable resins, a light radiating part that radiates ultraviolet light onto the resin storing part, and a substrate part where resins cured by the light radiating part are piled. Korean Patent No. 10-1647799 discloses a DLP-type 3D printer. 
     However, such a DLP-type 3D printer may only manufacture a shaped product that consists of a single material and that has a single color. 
     Accordingly, there is a need to develop a technology to solve the above-described problem. 
     Meanwhile, the above-described related art is technical information retained by this applicant for drawing the present invention, or obtained by this applicant during the process of drawing the present invention. Accordingly, it cannot be said that the above-described related art is a well-known technology that went public prior to the application of the present invention. 
     DETAILED DESCRIPTION OF THE INVENTION 
     Technical Problems 
     The present invention is directed to providing a three-dimensional printer. 
     Technical Solutions 
     According to one aspect of the present invention, a three-dimensional printer as a means to achieve the above-described aim includes a plurality of tanks storing liquid materials therein, a light radiating unit disposed at the lower portion of the plurality of tanks so as to radiate light, a switching unit disposed at the bottom of the tanks so as to transmit light corresponding to an axial direction cross sectional image of a shaped product formed in the tanks, out of light radiated by the light radiating unit; and a forming stage where a shaped product is formed at the lower portion thereof is configured to move up and down. 
     Advantageous Effects 
     A three-dimensional printer according to an embodiment of the present invention includes a plurality of tanks providing different photocurable liquid resins so as to generate various shaped products. 
     A three-dimensional printer according to an embodiment of the present invention is designed to cure various materials contained in a plurality of tanks with a single LED with no need to install light sources at each tank. 
     A three-dimensional printer according to an embodiment of the present invention may generate different-colored structures compared to conventional three-dimensional printers by taking a voxel as a basic unit of colors of an output. 
     A three-dimensional printer according to an embodiment of the present invention includes a plurality of tanks so as to manufacture various shaped products that consist of different materials and have different colors. 
     Shaped products, generated by a three-dimensional printer according to an embodiment of the present invention, form voxels by using a variety of colors, and the colors of voxels themselves may change depending on the arrangement of colors. 
     A cleanser may be stored in any one of the tanks included in a three-dimensional printer according to an embodiment of the present invention, and a cleansing unit is disposed between tanks adjacent to each other so as to clean a shaped product. 
     Advantages of the present invention are not limited to the above-described advantages, and other advantages of the present invention that have not been described, will be apparent to one of ordinary skill in the art to which the present invention pertains from the following description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view illustrating a configuration of a three-dimensional printer according to an embodiment of the present invention. 
         FIG. 2  is a plan view illustrating a configuration of a three-dimensional printer according to an embodiment of the present invention. 
         FIG. 3  is a front view illustrating a configuration of a three-dimensional printer according to an embodiment of the present invention. 
         FIG. 4  is a plan view illustrating a configuration of a three-dimensional printer according to another embodiment of the present invention. 
         FIG. 5  is a front view illustrating a configuration of a three-dimensional printer according to another embodiment of the present invention. 
         FIG. 6  is a view illustrating a theory in which a color of a voxel constituting a shaped structure printed out by a three-dimensional printer according to an embodiment of the present invention is formed. 
     
    
    
     MODE FOR CARRYING OUT THE INVENTION 
     Below, embodiments of the present invention will be described in detail with reference to the attached drawings such that one of ordinary skill in the art to which the present invention pertains can easily embody the present invention. However, the present invention may be embodied in various forms, and should not be construed as being limited to the embodiments set forth herein. Further, what is irrelevant to the description of the present invention will be excluded from the attached drawings so as to describe the present invention clearly, and like reference numerals denote like elements throughout the specification. 
     It should be understood that when an element is “connected” to another element, it means that one element may be “directly connected” to another element and that a third element may exist between one element and another element such that one element is “electrically connected” to another element. It should be further understood that the term “comprise” means including any other element but not precluding any another element unless specifically described to the contrary. 
     In this specification, the terms “left’ and “right” are used to describe a position of a specific element in  FIG. 3  but do not mean that the specific element is positioned on the left and on the right. 
     Like reference numerals denote like elements even when the like elements are illustrated in different drawings. Further, if necessary, elements in another drawing may be cited when a drawing is described. 
     Below, a three-dimensional printer  100  according to an embodiment of the present invention will be described in detail with reference to the attached drawings. 
       FIG. 1  is a perspective view illustrating a configuration of a three-dimensional printer  100  according to an embodiment of the present invention,  FIG. 2  is a plan view illustrating a configuration of a three-dimensional printer  100  according to an embodiment of the present invention, and  FIG. 3  is a front view illustrating a configuration of a three-dimensional printer  100  according to an embodiment of the present invention. 
     A three-dimensional printer  100  according to an embodiment of the present invention may include at least one tank  10  to  15 . The tank  10  to  15  is an element and a device that can store liquid materials necessary for creating a formed structure. 
     The tank  10  to  15  has a rectangular parallelepiped shape whose top is opened, and has a storing space S therein, in which a liquid material may be stored. The tank  10  to  15  may consist of a fluororesin film while the liquid material stored in the storing space S may include a curing resin or a resin (a material in which a photocurable plastic is melted) etc. that are cured by ultraviolet rays. The curable resin or resin is presented only as an example. Accordingly, any material that may be cured by ultraviolet rays may be stored in the tank  10  to  15 . 
     Meanwhile, the tank  10  to  15  may be arranged at the same height, and the arrangement and number of the tanks  10  to  15  may be determined on the basis of the sort and number of liquid materials. 
     That is, each tack  10  to  15  included in a three-dimensional printer  100  according to an embodiment of the present invention may store liquid materials that differ in color and that consist of different materials, and a cleanser for washing the liquid materials. The number, arrangement and position of the tanks may be determined on the basis of the sort and color of the liquid materials. For instance, a plurality of the tanks  10  to  15 , as illustrated in  FIGS. 1 to 3 , may be positioned in the X-axis and Y-axis directions. 
     Specifically, if only six colors (e.g. magenta, yellow, cyan, black, white and transparent colors) except the cleanser are used to obtain a shaped product, six tanks  10  to  15  may be positioned in the three-dimensional printer  100  so as to store different color liquid materials and may be positioned at the same height such that six tanks are positioned in groups of three in the X-axis direction of the three-dimensional printer  100  and positioned in groups of two in the Y-axis direction of the three-dimensional printer  100 , as illustrated in  FIG. 1 . Additionally, as another example, if a liquid material with another color and a cleanser, besides the six color liquid materials, are used to obtain a shaped product, a total of eight tanks may be positioned in the three-dimensional printer such that eight tanks are positioned in groups of four in the X-axis direction of the three-dimensional printer  100  and positioned in groups of two in the Y-axis direction of the three-dimensional printer  100 . 
     Meanwhile, a three-dimensional printer  100  according to an embodiment of the present invention may include a cleansing unit (invisible). 
     If a forming stage  35  that will be described hereunder moves into a certain tank  11  to  15  and then move into another tank  11  to  15 , liquid materials can be left. In this case, the cleansing unit (invisible) removes the left liquid materials. 
     The cleansing unit (invisible) may be positioned between a pair of tanks  11  to  15  adjacent to each other or the outer surfaces of the tanks  11  to  15 , and may have any configuration so as to remove the liquid materials left at the forming stage that will be described hereunder. For instance, a compressor etc. may be applied to the cleansing unit (invisible) so as to blow compressed air. 
     In this case, if compressed air is perpendicularly blown at the lower portion of the forming stage  35 , there is a possibility that the left liquid material is not discharged out of the forming stage  35 . Accordingly, compressed air may be obliquely blown at the lower portion of the forming stage  35 . 
     Meanwhile, the three-dimensional printer  100  may include a stage transferring unit  20  supporting the forming stage  35  so as to move the forming stage in the X-axis and Y-axis directions. 
     The stage transferring unit  20  may include a pair of moving frames  16 ,  17  and may include at least one first axis guide rod  21  extending from any one of the pair of moving frames  16 ,  17  to the other. 
     First, the pair of moving frames  16 ,  17  may be positioned at both sides of the tanks so as to face each other, the upper portion of each of the pair of moving frames  16 ,  17  may be disposed at a position higher than the position of the tanks  10  to  15 , and each moving frame  16 ,  17  may move along a second axis guide rod  22  and a third axis guide rod  23 . This will be described below. 
     Meanwhile, the forming stage  35  may slide along the first guide rod  21 . 
     Specifically, a through hole (invisible) may be formed at the forming stage  35 , and the first axis guide rod  21  may penetrate into and connect with the through hole. The forming stage  35  coupled to a first axis driving belt  22  moves along the first axis guide rod  21  as the first axis driving belt  22  rotates. 
     Specifically, the forming stage  35 , as illustrated in  FIGS. 1 to 3 , moves from the first moving frame  16  to the second moving frame  17 , or from the second moving frame  17  to the first moving frame  16  as the driving belt  22  is wound around a pair of first axis pulleys  25 ,  26  and rotates. 
     Further, the stage transferring unit  20  may include a second axis guide rod  22  and a third axis guide rod  31 , and the forming stage  35  may slide along the second axis guide rod  22  and the third axis guide rod  31 . 
     Specifically, the second axis guide rod  22  penetrates into and connects with the first moving frame  16  positioned on the left, out of both ends of the first axis guide rod  21  in the lengthwise direction thereof, and the third axis guide rod  31  penetrates into and connects with the second moving frame  17  positioned on the right, out of both ends of the first axis guide rod  21  in the lengthwise direction thereof such that the first moving frame  16  and the second moving frame  17  slide along the second axis guide rod  22  and the third axis guide rod  31 . By doing so, the forming stage  35  also moves along the second axis guide road  22  and the third axis guide rod  31 . 
     Meanwhile, a three-dimensional printer  100  according to an embodiment of the present invention may include at least one position adjusting motor  36 ,  37 . The position adjusting motors  36 ,  37  are configured to receive electric energy so as to provide mechanical energy such that the pulleys  25 ,  26 ,  27 ,  28  and the driving belts  23 ,  24  swivel. 
     Specifically, the first position adjusting motor  36 , as illustrated in  FIGS. 1 to 3 , may be positioned at any one of the first moving frame  16  and the second moving frame  17 . If the first position adjusting motor  36  is positioned at the first moving frame  16 , the left first axis pulley  25  swivels, and if the first position adjusting motor  36  is positioned at the second moving frame  17 , the right first axis pulley  26  swivels, while the first axis driving belt  23  wound around the left first axis pulley  25  and the right first axis pulley  26  also swivels. 
     Further, the second position adjusting motor  37  may be disposed at a certain position. Driving force generated from the second position adjusting motor  37  is delivered respectively to the second axis pulleys  27 ,  28  so as to swivel the second axis driving pulleys  27 ,  28  and the second axis driving belt  24  that are wound around the second axis pulleys  27 ,  28 . Finally, the first moving frame  16  and the second moving frame  17  move along the second axis guide rod  22  and the third axis guide rod  31 . 
     Meanwhile, a three-dimensional printer  100  according to an embodiment of the present invention may include a pair of actuators  32 ,  33  and two pairs of perpendicular guide rods  38 ,  39 . Each of the actuators  32 ,  33  uses an LM guide and a ball screw so as to adjust the height of an element connected to the actuator  32 ,  33 . Detailed description regarding this will not be provided because this is well-known. 
     According to a three-dimensional printer  100  of an embodiment of the present invention, the heights of the second axis guide rod  22  and the third axis guide rod  31  may be adjusted by a pair of actuators  32 ,  33 . By doing so, the height of the forming stage  35  may also be adjusted. Specifically, the left actuator  32  is disposed between a pair of left perpendicular guide rods  38  and disposed at the center of both ends of the second axis guide rod  22  in the lengthwise direction thereof, and the right actuator  33  is disposed between a pair of right perpendicular guide rods  39  and disposed at the center of both ends of the third axis guide rod  31  in the lengthwise direction thereof, such that the heights of the second axis guide rod  22  and the third axis guide rod  31  are adjusted. 
     Meanwhile, a three-dimensional printer  100  according to an embodiment of the present invention may include a forming stage  35 . 
     The forming stage  35  to which a shaped product obtained by means of the curing of inks may be configured to have a proper shape such that the shaped product is attached. 
     Specifically, as illustrated in  FIG. 1 , a cross section of each of the tanks  11  to  15 , which are parallel to the ground surface, is configured as a rectangle in the axial direction, and a cross section of the lower surface of the forming stage  35  may be configured as a rectangle that is proper for the forming stage  35  so as to go into each of the tanks  11  to  15  and to attach the shaped product. 
     Additionally, the rectangular plate-shaped forming stage has been provided only as an example. If a three-dimensional printer  100  according to an embodiment of the present invention includes a tank with a circular cross section parallel to the ground surface, the forming stage  35  may be configured to have a cylindrical shape. 
     More specifically, the forming stage  35  may be configured to move up and down and may have a shaped product at the lower portion thereof. If the forming stage  35  moves down and is disposed near the bottom of the tank  11  to  15 , a light radiating unit  41  radiates light towards the tank, liquid materials are cured by the light radiated by the light radiating unit  41 , a shaped product is formed at the lower portion of the forming stage  35 , and then the forming stage moves up again. 
     Meanwhile, a three-dimensional printer  100  according to an embodiment of the present invention may include a light radiating unit  41 . 
     The light radiating part  41  is disposed at the lower portion of each of the tanks  11  to  15  so as to cure the liquid materials stored in the tanks  11  to  15 . 
     The light radiating unit  41  may be configured to radiate enough light to each of the tanks  11  to  15 . For instance, a plurality of light-emitting diodes (LED) radiating light ranging from 390 nm to 420 nm may be arranged in the X-axis and Y-axis directions. If the light radiating unit  41  consists of a plurality of LEDs, the light radiating unit  41  evenly radiates light on the entire surface towards the tanks  11  to  15  unlike conventional projectors. 
     Specifically, the light radiating units  41  may be disposed so as to correspond to each of the tanks  11  to  15 , a single light radiating unit  41  may be formed so as to correspond to a total of the X-Y axial direction cross sections of all the tanks  10  to  15 , or a light radiating unit  41  may be disposed so as to correspond to each group after certain tanks  11  to  15  are formed into groups. 
     A three-dimensional printer  100 , as illustrated in  FIG. 2 , includes a single light radiating unit  41  so as to correspond to the X-Y axial direction cross sections of all the tanks  10  to  15 , and the light radiating unit  41  is configured to radiate light onto all the tanks  10  to  15 . A switching unit  43  that will be described below may selectively transmit the light radiated onto each of the tanks  11  to  15  by means of the light radiating unit  41 . 
     Meanwhile, a three-dimensional printer  100  according to an embodiment of the present invention may include a supporting unit  42 . 
     The supporting unit  42  may consist of glass with high light transmission so as to increase the intensity of the switching unit  43 . The supporting unit  42  may consist of a material that is more ductile and malleable than that of the switching unit  43  that will be described below, and may consist of a material that is stronger than that of the switching unit  43  so as to resist shocks, shear force and tensile stress. The supporting unit  42  may be attached to the lower portion of the switching unit  43  so as to increase the intensity of the switching unit  43  even when a force strong enough to damage the switching unit  43  is exerted on the switching unit  43 , thereby preventing damage to the switching unit  43 . 
     Further, the supporting unit  42  may consist of a transparent material that can transmit light such as diamant glass, transparent plastics etc. Diamant glass, transparent plastics etc. are presented only as examples. Accordingly, any transparent materials may be applied to the supporting unit  42 . 
     Meanwhile, a three-dimensional printer  100  according to an embodiment of the present invention may include a switching unit  43 . 
     The switching unit  43  is disposed at the bottom of the tanks  11  to  15  so as to selectively transmit light corresponding to the axial direction (X-Y axis) cross sectional image of a shaped product formed in the tanks  11  to  15 , out of the light radiated by the light radiating unit  41 . 
     Specifically, the switching unit  43  may be configured as a liquid crystal display (LCD), and the light radiated by the light radiating unit  41  may be transmitted through the LCD or may not be transmitted through the LCD according to whether an electric current is applied to the LCD. The method for operating an LCD will not be described in detail because it is well-known. 
     Meanwhile, the configuration of a three-dimensional printer  200  according to another embodiment of the present invention will be described hereunder with reference to  FIGS. 3 to 4 . 
       FIG. 4  is a plan view illustrating a configuration of a three-dimensional printer  200  according to another embodiment of the present invention, and  FIG. 5  is a front view illustrating a configuration of a three-dimensional printer  300  according to another embodiment of the present invention. 
     Unless additional technologies of another embodiment of the present invention that will be described below are disclosed, all the configurations included in a three-dimensional printer  200 ,  300  according to the above-described embodiment of the present invention are construed as being included in another embodiment of the present invention. 
     According to a three-dimensional printer of another embodiment of the present invention, tanks  10  to  15  may be disposed at the same height in a circular way so as to swivel around the central axis C, and a swiveling motor (invisible) may be disposed at the central axis of the tanks  10  to  15 . 
     Specifically, according to a three-dimensional printer of another embodiment of the present invention, if a certain material is used to form a shaped structure, tanks  11  to  15  storing the material move to the lower portion of the forming stage  35 , and the forming stage  35  moves up and down at the upper portion of the tanks  11  to  15  disposed at the lower portion of the forming stage  35  so as to form a shaped structure, as illustrated in  FIG. 4 . 
     The theory of swiveling a circular structure with a swiveling motor will not be described in detail because it is well-known. 
     Further, according to a three-dimensional printer of another embodiment of the present invention, tanks  10  to  15  are arranged up and down with respect to each other, and may selectively move to the lower portion of the forming stage  35 . 
     Specifically, according to a three-dimensional printer of another embodiment of the present invention, tanks  10  to  15  may be disposed in the form of a chest of drawers, as illustrated in  FIG. 5 . A supporting unit  42  and a switching unit  43  may be disposed at the lower portion of each of the tanks  10  to  15 . Light radiating units  41  may also be disposed respectively at the lower portions of the switching units  43 . When each of the tanks  10  to  15  selectively moves to the lower portion of the forming stage  35 , the supporting unit  42  and the switching unit  43  that are disposed at the lower portion of each tank  10  to  15  may also move, and any one of an actuator, a motor, a hydraulic cylinder and a pneumatic cylinder may be disposed at one side of the tanks  10  to  15  so as to move the tanks  10  to  15 . 
     Below, features of a shaped product formed by a three-dimensional printer  100 ,  200 ,  300  according to an embodiment of the present invention will be described with reference to  FIG. 6 .  FIG. 6  is a view illustrating a theory in which a voxel color, constituting a shaped structure printed out by a three-dimensional printer according to an embodiment of the present invention, is formed. 
     The smallest unit consisting of a two-dimensional image, or a small square dot is referred to as a pixel. The quality of an image is determined by the number of pixels consisting of the image. Each pixel displays colors by a combination of red, green and blue. 
     An image generated by a three-dimensional printer is three-dimensional. Accordingly, instead of a pixel in a two-dimensional image, the term voxel is used to refer to the image generated by a three-dimensional printer. That is, a shaped product consisting of a large number of voxels is a product of a high standard and of a high quality. 
     A voxel, as illustrated in  FIG. 6 , is a three-dimensional unit, and the color of a voxel changes according to the colors included in the voxel, the positions of the colors, and the direction in which a person sees the voxel. Accordingly, the color included in the voxel, and the position of the color included in the voxel as well have to be determined so as to decide on the color of a certain voxel. 
     The descriptions of the present invention have been provided as an example, and it will be understood that one of ordinary skill in the art to which the present invention pertains may modify the present invention in different forms without departing from the technical spirit and essential features of the present invention. Thus, it should be understood that the embodiments set forth herein have been provided only as examples but not intended to limit the present invention. For instance, elements described as an integrated form may be separately embodied, and elements described as a separated form may be integrally embodied. 
     The scope of the present invention should be determined by the attached claims rather than the description of the invention, and all the meanings and scope of the claims, and all the modifications or modified forms drawn from equivalents should be construed as being included in the scope of the present invention.