Patent Publication Number: US-2020282643-A1

Title: Three dimensional printing device

Description:
This is a Continuation of U.S. application Ser. No. 15/646,250, filed Jul. 11, 2017. This continuation application claims the benefit of U.S. patent application Ser. No. 15/646,250, filed Jul. 11, 2017, the contents of which are incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to a printing device, and more particularly to a three dimensional printing device. 
     BACKGROUND OF THE INVENTION 
     In current three dimensional printing technology, a bottom-up Stereo Lithography Apparatus (bottom-up SLA) has been developed. The bottom-up SLA can produce a fine product. A printing platform will be lowered and entirely immersed into a photocured material as the bottom-up SLA performs printing. After that, the photocured material will be illuminated and solidified, and the printing platform will be slowly raised to form a plurality of stacked solid-state patterns on a bottom surface of the printing platform, thereby forming a printed product. However, the above photocured material typically have a predetermined viscosity, that is, most of the typical photocured materials have a low fluidity so that the printing platform immersed into the photocured material will be subjected to uneven buoyancy, thereby causing the printing platform being tilted and not horizontal, and reducing the fineness of printing. 
     SUMMARY OF THE INVENTION 
     An embodiment of the present invention provides a three dimensional printing device including a plane and a pusher mechanism. The plane is capable of putting a photocured material. The pusher mechanism has a contact end above the plane, wherein the contact end is capable of and removing a portion of the photocured material, and wherein a remnant thickness of the removed photocured material is larger than a thickness of a layer of cured pattern. Wherein entire of the pusher mechanism does not contact the plane. Wherein the pusher mechanism is nonrotatable with respect to the plane. 
     Another embodiment of the present invention provides a three dimensional printing device including a plane, a moveable supplying mechanism and a detector. The plane is capable of putting a photocured material. The supplying mechanism is disposed above the plane, wherein the supplying mechanism is configured to: supply the photocured material to the plane. The detector is disposed above the plane and configured to transmit a signal when a thickness of the photocured material above the plane reaches a predetermined thickness, wherein the predetermined thickness is less than 1 mm. 
     Another embodiment of the present invention provides a three dimensional printing device including a plane, a projector, a printing platform, a platform driving mechanism and a detector. The plane is capable of putting a photocured material. The projector is configured to emit light capable of curing the photocured material to form a layer of cured pattern. The printing platform has a lower surface capable of attaching the layer of cured pattern. The platform driving mechanism is configured to drive the printing platform to be immersed into the photocured material. The detector is disposed above the plane and configured to transmit a signal when a maximum immersing depth of the lower surface to a top surface of the photocured material reaches a predetermined depth, wherein the predetermined depth is less than 1 mm. 
     Due to the pusher mechanism or the supplying mechanism used in the invention, so that the thickness of the photocured material above the plane can become thinner (e.g. less than 1 mm). Thus, a volume of the printing platform being immersed into the photocured material can be reduced to dramatically reduce buoyancy, thereby preventing the printing platform from being tilted due to the uneven buoyancy applied thereto, and thereby improving the issue of reducing the fineness of printing due to the uneven printing device. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will become more readily apparent to those ordinarily skilled in the art after reviewing the following detailed description and accompanying drawings, in which: 
         FIGS. 1A and 1B  illustrate schematic diagrams of a three dimensional printing device according to an embodiment of the invention; and 
         FIG. 2  illustrates a schematic diagram of a three dimensional printing device according to another embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     The present invention will now be described more specifically with reference to the following embodiments. It is to be noted that the following descriptions of preferred embodiments of this invention are presented herein for purpose of illustration and description only. It is not intended to be exhaustive or to be limited to the precise form disclosed. 
     Referring to  FIGS. 1A and 1B , the three dimensional printing device  100  includes a pusher mechanism  110 , a putting base  120 , a printing platform  130 , a projector  140 , and a driving mechanism  150 . The putting base  120  is capable of putting a photocured material M 1  and has a plane  121  putting the photocured material M 1 . The photocured material M 1  may be a liquid having a good fluidity or a fluid which is not easily flowable, and the invention is not limited thereto. 
     The pusher mechanism  110  has a contact end  111  above the plane  121 , being configured to contact and remove a portion of the photocured material M 1 , wherein the pusher mechanism  110  can be, for example, a scraper or a roller. The driving mechanism  150  connects the pusher mechanism  110  and drives the pusher mechanism  110  to move over the plane  121  so that the contact end  111  of the pusher mechanism  110  is able to remove a portion of the photocured material M 1 . Therefore, a remnant thickness of the removed photocured material M 1  over the plane  121  can be reduced to, for example, less than 1 mm, but the present invention is not limited thereto. The driving mechanism  150  may include a power source and a driving assembly connected to the power source, wherein the power source can be, for example, a motor and the driving assembly is connected to the pusher mechanism  110  and may be operated by gears, pulleys, belts or other mechanisms, or combinations of the above mechanisms. Therefore, the driving mechanism  150  can drive the pusher mechanism  110  to move above the plane  121 , so that the contact end  111  of the pusher mechanism  110  is able to remove a portion of the photocured material M 1 . 
     The printing platform  130  is disposed above the plane  121  and may move upward and downward along a direction toward and away from the plane  121 . More specifically, the three dimensional printing device  100  may include a platform driving mechanism  160  which connects the printing platform  130 , wherein the platform driving mechanism  160  may include a telescopic lever  161 , a cantilever  162 , and a motor  163 . The motor  163  can be connected and retracted through the driving assembly in the cantilever  162  to drive the printing platform  130  connected to the telescopic lever  161  to move upward and downward. Therefore, the platform driving mechanism  160  can move the printing platform  130  upward and downward toward the direction of toward and away from the plane  121 , but the present invention is not limited thereto. 
     The printing platform  130  has a lower surface  132  used for contacting and being immersed into the photocured material M 1 , and the projector  140  may emit light L 1  toward the plane  121  and the lower surface  132 , and the light L 1  can penetrate the plane  121  to thereby illuminate the photocured material M 1 , thereby curing the photocured material M 1  so as to form a layer of cured pattern F 1  (e.g. as shown in  FIG. 1B ) above the lower surface  132 . Thus, the lower surface  132  of the printing platform  130  can be used to attach the layer of cured pattern F 1 . In addition, the layer of cured pattern F 1  is a basic unit for forming a printed product. That is, the printed product is formed by stacking a plurality of layers of cured patterns F 1 , and at least two of these stacked layers of cured patterns F 1  may be different from each other to form a plurality of final products with different appearances. 
     When the three dimensional printing device  100  performs printing, the photocured material M 1  is first placed above the plane  121 . Next, the driving mechanism  150  drives the pusher mechanism  110  to move above the plane  121  to remove a portion of the photocured material M 1  so that the photocured material M 1  above the plane  121  is thinned, for example, by making a thickness of the photocured material M 1  above to the plane  121  being less than 1 mm. Thereafter, the platform driving mechanism  160  drives the printing platform  130  to move in a direction toward the plane  121  so that the lower surface  132  of the printing platform  130  can be immersed into the photocured material M 1 . As shown in  FIG. 1A , a maximum immersion depth D 1  of the lower surface  132  to a top surface M 11  of the photocured material M 1  may be less than 1 mm after the printing platform  130  is immersed into the photocured material M 1 . Thereafter, the projector  140  emits light L 1  which penetrates the plane  121  and illuminates the photocured material M 1  so that the photo-cured material M 1  illuminated by the light L 1  is cured to form the layer of cured pattern F 1  above the lower surface  132 , wherein a thickness TM 1  of the photocured material M 1  after being removed by the pusher mechanism  110  is larger than a thickness TF 1  of the layer of cured pattern F 1 , as shown in  FIG. 1B . Thereafter, the projector  140  may emit a plurality of different lights L 1  to form a plurality of layers of cured patterns F 1  with different appearances and being stacked with each other, thereby completing the printed product, and the platform driving mechanism  160  drives the printing platform  130  to move in a direction away from the plane  121 , thereby detaching the photocured material M 1 . 
       FIG. 2  illustrates a schematic diagram of a three-dimensional printing device according to another embodiment of the present invention. Referring to  FIG. 2 , it is a schematic view of the three-dimensional printing device  200 , and differences between the three-dimensional printing apparatuses  200  and  100  will be described below, and the same features will not be further described. 
     The three-dimensional printing device  200  of the present embodiment includes a supplying mechanism  210  disposed above the plane  121  but does not include the pusher mechanism  110  described in the foregoing embodiment. The supplying mechanism  210  may be a nozzle and the driving mechanism  150  may be connected to the supply mechanism  210  and may drive the supply mechanism  210  to move above the plane  121 . Thus, the three-dimensional printing device  200  can provide the photocured material M 1  to the plane  121  with the supplying mechanism  210  to spray a thin layer of photocured material M 1  with a thickness TM 21  of, for example, less than 1 mm above the plane  121 . In addition, in the present embodiment, the supplying mechanism  210  may stop providing the photocured material M 1  to the plane  121  prior to the printing platform  130  contacts the photocured material M 1  during the printing, but in other embodiments, even if the printing platform  130  is immersed into the photocured material M 1 , the supplying mechanism  210  can continuously provide the photocured material M 1  to the plane  121 , and the present invention is not limited thereto. 
     As disclosed above, the embodiments of present invention makes it possible to make the photocured material above the plane thinner by using a pusher mechanism or a supplying mechanism. In this way, as the printing platform contacts the photocured material for printing, the thin photo-cured material can significantly reduce the buoyancy generated by the printing platform, so that the printing platform will not tilt due to the buoyancy, thereby improving issues caused by uneven buoyancy of the printing platform, and effectively improve the printing fineness. 
     While the invention has been described in terms of what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention needs not be limited to the disclosed embodiment. On the contrary, it is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims which are to be accorded with the broadest interpretation so as to encompass all such modifications and similar structures.