Patent Publication Number: US-2023140340-A1

Title: Printing device

Description:
CROSS REFERENCE TO THE RELATED APPLICATIONS 
     This application is based upon and claims priority to Chinese Patent Application No. 202122637343.7 filed on Oct. 29, 2021, the entire contents of which are incorporated herein by reference. 
     TECHNICAL FIELD 
     The present application relates to the technical field of printers, and in particular to a printing device. 
     BACKGROUND 
     The photo-curing printing technology includes the stereo lithography appearance (SLA) printing technology, the liquid crystal display (LCD) printing technology and the digital light processing (DLP) printing technology. However, most of the existing photo-curing printing technologies can only perform monochrome printing, such that photo-curing printers have limitations when printing models. 
     SUMMARY 
     The present application provides a printing device, so as to solve the problem that a photo-curing printer can not print color models. 
     Embodiments of the present application provide a printing device. The printing device includes: 
     a base; 
     a printing platform, the printing platform being connected to the base; 
     a printing bracket, the printing bracket being fixed on the base; and 
     a printing head assembly, the printing head assembly being connected to the printing bracket and being arranged above the printing platform, and the printing head assembly including a bearing member, a discharging assembly and an optical assembly, wherein the discharging assembly and the optical assembly are both arranged on the bearing member, the discharging assembly is used for providing printing materials of at least two colors for the printing platform, and the optical assembly is used for curing the printing materials on the printing platform. 
     In the embodiments of the present application, the printing platform is connected to the base, the printing bracket is fixed on the base, the printing head assembly is connected to the printing bracket and is arranged above the printing platform, and when the printing device is operating, the discharging assembly provides the printing materials of at least two colors for the printing platform, and the printing materials on the printing platform are cured by means of the optical assembly, to implement three-dimensional color printing on the printing platform. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In order to more clearly illustrate the technical solutions of the present application, the accompanying drawings used in the description of the embodiments or the prior art will be briefly described below. Apparently, the accompanying drawings in the following description are only some embodiments of the present application, and those of ordinary skill in the art can further obtain other accompanying drawings according to the accompanying drawings without involving any inventive effort. 
         FIG.  1    is a schematic structural diagram of a printing device according to an embodiment of the present application; 
         FIG.  2    is an exploded view of a printing device according to another embodiment of the present application; 
         FIG.  3    is a schematic structural diagram of a printing head assembly according to another embodiment of the present application; and 
         FIG.  4    is a schematic structural diagram of another printing head assembly according to another embodiment of the present application. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present application. Apparently, the embodiments described are some rather than all of the embodiments of the present application. The embodiments described below and features in the embodiments can be combined with each other without conflict. All other embodiments obtained by those of ordinary skill in the art on the basis of the embodiments of the present application without involving any inventive effort fall within the scope of protection of the present application. 
     The terms “first”, “second”, etc. in the embodiments of the present application are used to distinguish similar objects, and are not necessarily used to describe a specific order or a precedence order. In addition, the terms “include” and “have” and any variation thereof are intended to cover a non-exclusive inclusion, for example, a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but can include other steps or units not explicitly listed or inherent to such a process, method, product or apparatus. Furthermore, “and/or” used in the present application represents at least one of the connecting objects, such as A and/or B and/or C, which represents including the seven instances of A alone, B alone, C alone, and A and B simultaneously, B and C simultaneously, A and C simultaneously, and A, B, and C simultaneously. 
     With reference to  FIG.  1   ,  FIG.  1    is a schematic structural diagram of a printing device according to an embodiment of the present application. As shown in  FIG.  1   , the printing device includes a base  100 , a printing platform  200 , a printing bracket  300  and a printing head assembly  400 . 
     The printing platform  200  is connected to the base  100 . 
     The printing bracket  300  is fixed on the base  100 . 
     The printing head assembly  400  is connected to the printing bracket  300  and is arranged above the printing platform  200 . The printing head assembly  400  includes a bearing member  410 , a discharging assembly  420  and an optical assembly  430 . The discharging assembly  420  and the optical assembly  430  are both arranged on the bearing member  410 , the discharging assembly  420  is used for providing printing materials of at least two colors for the printing platform  200 , and the optical assembly  430  is used for curing the printing materials on the printing platform  200 . 
     It should be understand that the discharging assembly  420  is used for providing the printing materials of at least two colors for the printing platform  200 , and by means of a relative movement between the discharging assembly  420  and the printing platform  200 , the discharging assembly  420  can provide the printing materials of corresponding colors for corresponding positions on the printing platform  200 . Moreover, the printing materials can be ultraviolet (UV) water-based ink, the UV water-based ink is provided for the printing platform  200  by means of the discharging assembly  420 , and the UV water-based ink on the printing platform  200  is then irradiated by means of the optical assembly  430  to cure the UV water-based ink, so as to print one layer of a three-dimensional printing. Thus, layers of the three-dimensional printing is printed layer by layer by changing the distance between the discharging assembly  420  and the printing platform  200 . 
     As shown in  FIGS.  2  and  3   , the discharging assembly  420  includes at least two storage boxes  421 . The at least two storage boxes  421  are used for storing printing materials of different colors. 
     A nozzle assembly (not shown in the drawings) is provided on the side of the storage boxes  421  opposite to the printing platform  200 , and is used for jetting the printing material to the printing platform  200 . 
     Specifically, the printing materials of different colors can be stored in different storage boxes  421 , respectively, and jetted to the printing platform  200  by means of the nozzle assemblies of the storage boxes  421 . In some embodiments, the nozzle assemblies can include a plurality of micro-holes (not shown in the drawings) provided at the bottom of the storage box  421  used for jetting printing materials. The plurality of micro-holes are uniformly arranged at the bottom of the storage boxes  421 . For example, a plurality of micro-holes can be arranged in two rows at equal intervals at the bottom of the storage box  421 . 
     In some embodiments, the number of storage boxes  421  can be set according to actual requirements, and the corresponding nozzle assemblies can be controlled to jet the printing materials to the printing platform  200  according to the color of a product to be printed. 
     In the embodiment, the at least two storage boxes  421  are used for storing the printing materials of different colors, and the nozzle assemblies are provided on the storage boxes  421  opposite to the printing platform  200 , and is used for jetting the printing material to the printing platform  200 , to print at least two colors on the printing platform  200 . 
     As shown in  FIG.  3   , feeding ports  4211  are also provided on the storage boxes  421 , and feeding ports  4211  are used for adding the printing material into the storage boxes  421 . 
     The feeding ports  4211  can be in communication with feeding boxes, the feeding boxes can be used for storing a large amount of printing materials of different colors, and during printing, when the printing materials stored in the storage boxes  421  are not enough, the printing materials of corresponding colors can be supplemented by means of the feeding ports  4211 . Moreover, the printing materials being added into the storage boxes  421  by means of the feeding ports  4211  can accordingly reduce the storage capacity of the storage boxes  421 , that is, the size and weight of the storage boxes  421  can accordingly be reduced, and it is necessary to continuously move the storage boxes  421  during printing to implement three-dimensional printing on the printing platform  200 , such that small size and weight of the storage boxes  421  can also contribute to improving printing precision. 
     In the embodiment of the present application, the printing platform  200  is connected to the base  100 , the printing bracket  300  is fixed on the base  100 , the printing head assembly  400  is connected to the printing bracket  300  and is arranged above the printing platform  200 , and when the printing device runs, the discharging assembly  420  provides the printing materials of at least two colors for the printing platform  200 , and the printing materials on the printing platform  200  are cured by means of the optical assembly  430 , to implement three-dimensional color printing on the printing platform  200 . 
     As shown in  FIGS.  2  and  3   , the printing device further includes a light shielding member  500 . The light shielding member  500  is movably arranged between the nozzle assemblies and the printing platform  200 , so as to switch the nozzle assemblies between a state in which the nozzle assemblies are shielded by the light shielding member  500  and a state in which the nozzle assemblies are not shielded by the light shielding member  500 . 
     It should be understand that in the state in which the nozzle assemblies are not shielded by the light shielding member  500 , the nozzle assemblies can jet the printing materials onto the printing platform  200 ; and when it is necessary to cure the printing materials on the printing platform  200  by means of the optical assembly  430 , the nozzle assemblies can be in the state in which the nozzle assemblies are shielded by the light shielding member  500 , such that the printing materials left at outlets of the nozzle assemblies are prevented from being cured by the optical assembly  430 , that is, the nozzle assemblies are prevented from being blocked. 
     The light shielding member  500  can be made of a material having excellent light shielding performance, such that light from the optical assembly  430  is prevented from passing though the light shielding member  500  to cure the printing materials left at the outlets of the nozzle assemblies. 
     In the embodiment, the light shielding member  500  is movably arranged between the nozzle assemblies and the printing platform  200 , so as to switch the nozzle assemblies between a state in which the nozzle assemblies are shielded by the light shielding member  500  and a state in which the nozzle assemblies are not shielded by the light shielding member  500 , such that the nozzle assemblies are prevented from being blocked due to irradiation of the optical assembly  430 . 
     As shown in  FIGS.  2  and  3   , at least two first through holes  510  are provided in the light shielding member  500  at intervals. 
     In the state in which the nozzle assemblies are not shielded by the light shielding member  500 , the at least two first through holes  510  are respectively located at vertical projection positions of the nozzle assemblies of the at least two storage boxes  421  on the light shielding member  500 . 
     In the state in which the nozzle assemblies are shielded by the light shielding member  500 , positions of the at least two first through holes  510  do not overlap the vertical projection positions of the nozzle assemblies of the at least two storage boxes  421  on the light shielding member  500 . 
     As shown in  FIG.  3   , the light shielding member  500  can be a light shielding plate, and at least two first through holes  510  are provided in the light shielding plate at intervals, such that in the state in which the nozzle assemblies are not shielded by the light shielding member  500 , the at least two first through holes  510  are respectively located at the vertical projection positions of the nozzle assemblies of the at least two storage boxes  421  on the light shielding member  500 , that is, the printing materials jetted from the nozzle assemblies can pass through the first through holes  510  to the printing platform  200 ; and in the state in which the nozzle assemblies are shielded by the light shielding member  500 , the positions of the at least two first through holes  510  do not overlap the vertical projection positions of the nozzle assemblies of the at least two storage boxes  421  on the light shielding member  500 , that is, the positions where the first through holes  510  are not provided in the light shielding plate are located directly below the nozzle assemblies, and the light shielding plate can block a light propagation path from the optical assembly  430  to the nozzle assemblies. 
     Further, first through holes  510  can be sized to match the nozzle assemblies. The nozzle assembly including two rows of micro-holes is taken as an example. A first through hole  510  can be a rectangular through hole, a length of the rectangular through hole can match that of the two rows of micro-holes, and a width of the rectangular through hole can match that of the two rows of micro-holes. The above matching arrangement can be understood as that the size of a rectangular through hole is slightly greater than the size of the two rows of micro-holes projected on the light shielding member  500 , such that in the state in which the nozzle assemblies are not shielded by the light shielding member  500 , the printing materials jetted from the nozzle assemblies are not shielded by the light shielding member  500  , and in the state in which the nozzle assemblies are shielded by the light shielding member  500 , the light shielding member  500  can shield light emitted from the optical assembly  430  to the nozzle assembly as much as possible. 
     The light shielding member  500  can also include a plurality of light shielding plates ( 520 ). The first through holes  510  are formed at intervals by the plurality of light shielding plates ( 520 ) arranged at intervals, a dimension of the first through hole  510  depends on a distance between adjacent light shielding plates ( 520 ), that is, the distance between the adjacent light shielding plates ( 520 ) needs to be greater than the dimension of the nozzle assembly projected on the light shielding member  500 , or the distance between the adjacent light shielding plates ( 520 ) needs to be equal to the dimension of the nozzle assembly projected on the light shielding member, such that in the state in which the nozzle assemblies are not shielded by the light shielding member  500 , the printing material jetted from the nozzle assembly is not shielded by the light shielding member  500 , and the dimension of one of the light shielding plates ( 520 ) also needs to be greater than that of the nozzle assembly on the light shielding member  500 , or the dimension of one of the light shielding plates ( 520 ) also needs to be equal to that of the nozzle assembly on the light shielding member  500 , such that in the state in which the nozzle assemblies are shielded by the light shielding member  500 , the light shielding member  500  can shield the nozzle assembly. 
     As shown in  FIGS.  2  and  3   , the printing device further includes a driving assembly  600 . The driving assembly  600  includes a closed synchronous belt  610 , a driving mechanism  620  and a synchronous wheel  630 . The closed synchronous belt  610  is connected to the light shielding member  500 , an output shaft  621  of the driving mechanism  620  is located at a first end of the closed synchronous belt  610 , the output shaft  621  is connected to the closed synchronous belt  610 , the synchronous wheel  630  is located at a second end of the closed synchronous belt  610  opposite to the first end, and the synchronous wheel  630  is connected to the closed synchronous belt  610 . 
     The driving mechanism  620  is used for driving the output shaft  621  to rotate to drive the closed synchronous belt  610  to move, so as to drive the light shielding member  500  connected to the closed synchronous belt  610  to switch between the state in which the nozzle assemblies are shielded and the state in which the nozzle assemblies are not shielded. 
     The closed synchronous belt  610  is connected to the light shielding member  500 , that is, the light shielding member  500  moves along with a movement of the closed synchronous belt  610 . 
     As shown in  FIG.  3   , the output shaft  621  of the driving mechanism  620  can be connected to a synchronous wheel  630  as a drive wheel  640 , and the drive wheel  640  is connected to the closed synchronous belt  610 . Specifically, the drive wheel  640  can be in meshed connection with an inner surface at one end of the closed synchronous belt  610 , the synchronous wheel  630  is in meshed connection with an inner surface at the other end of the closed synchronous belt  610 , or the synchronous wheel  630  is in engaged connection with an inner surface at the other end of the closed synchronous belt  610 , and the drive wheel  640  and the output shaft  621  of the driving mechanism  620  are coaxially arranged. The output shaft  621  is rotated to drive the drive wheel  640  to synchronously rotate, such that the closed synchronous belt  610  is driven to move to switch the light shielding member  500  connected to the closed synchronous belt  610  between the state in which the nozzle assemblies are shielded and the state in which the nozzle assemblies are not shielded. 
     In some embodiments, the output shaft  621  of the driving mechanism  620  can also be connected to a driving gear, and the driving gear is coaxially arranged with the output shaft  621 . The driving gear is connected to the closed synchronous belt  610 , and the output shaft  621  is rotated to drive the driving gear to synchronously rotate, such that the closed synchronous belt  610  is driven to move to switch the light shielding member  500  connected to the closed synchronous belt  610  between the state in which the nozzle assemblies are shielded and the state in which the nozzle assemblies are not shielded. 
     In the embodiment, the driving mechanism  620  is used for driving the output shaft  621  to rotate to drive the closed synchronous belt  610  to move, so as to drive the light shielding member  500  connected to the closed synchronous belt  610  to switch between the state in which the nozzle assemblies are shielded and the state in which the nozzle assemblies are not shielded. 
     As shown in  FIGS.  2  and  3   , the bearing member  410  includes a first bearing plate  411  and a second bearing plate  412 . A first side of the first bearing plate  411  is perpendicularly connected to a first side of the second bearing plate  412 , the first bearing plate  411  is connected to the printing bracket  300 , and the optical assembly  430  is arranged on a second side of the second bearing plate  412  opposite to the first side. 
     A second through hole is provided in the second bearing plate  412 , and the discharging assembly  420  is used for providing the printing materials of at least two colors for the printing platform  200  by means of the second through hole. 
     The first bearing plate  411  is used for being connected to the printing bracket  300 , the second bearing plate  412  is used for arranging the optical assembly  430  and the discharging assembly  420 , and the discharging assembly  420  can provide the printing materials of at least two colors for the printing platform  200  by means of the second through hole provided in the second bearing plate  412 . 
     In the embodiment, the bearing member  410  includes the first bearing plate  411  and the second bearing plate  412 . The first side of the first bearing plate  411  is perpendicularly connected to the first side of the second bearing plate  412 . The first bearing plate  411  is connected to the printing bracket  300 , and the second bearing plate  412  is used for bearing the discharging assembly  420  and the optical assembly  430 , such that a bearing effect of the bearing member  410  can be improved while the bearing member  410  is connected to the printing bracket  300 . 
     As shown in  FIG.  4   , the optical assembly  430  includes a movable connector  431  and a light emitting device  432 . The light emitting device  432  is connected to the bearing member  410  by means of the movable connector  431 . 
     The movable connector  431  is used for adjusting a light emitting direction of the light emitting device  432 . 
     An angle and position of the light emitting direction of the light emitting device  432  relative to the nozzle assembly can be adjusted according to actual requirements. In some embodiments, as shown in  FIG.  4   , the movable connector  431  can include: a fourth guide rail  4311 , a fixing block  4312 , a fifth guide rail  4313 , a first connecting column  4314  and a second connecting column  4315 . A first end of the fourth guide rail  4311  is fixedly connected to the bearing member  410  by means of the first connecting column  4314 , the first connecting column  4314  is arranged perpendicular to a lengthwise direction of the fourth guide rail  4311 , a fourth sliding groove extending in the lengthwise direction of the fourth guide rail  4311  is provided in the fourth guide rail  4311 , a first end of the second connecting column  4315  is in rolling connection with the fourth sliding groove, and the light emitting direction can be adjusted to change along the fourth sliding groove by controlling the position of the second connecting column  4315  in the fourth sliding groove. A third through hole  43121  is provided in the fixing block  4312 , the second connecting column  4315  penetrates the third through hole  43121  and is connected to the third through hole  43121 , that is the second connecting column  4315  penetrates the third through hole  43121  and is connected to walls of the third through hole  43121 , and the light emitting direction can be adjusted to change in an extending direction of the second connecting column  4315  by controlling the position of the fixing block  4312  on the second connecting column  4315 . A fifth sliding groove extending in a lengthwise direction of the fifth guide rail  4313  is provided in the fifth guide rail  4313 , the lengthwise direction of the fifth guide rail  4313  is perpendicular to that of the fourth guide rail  4311 , one end of a side surface of the fixing block  4312  is in rolling connection with the fifth sliding groove, the light emitting device  432  is fixedly arranged on the surface of the fifth guide rail  4313  opposite to the printing platform  200 , and the light emitting direction can be adjusted to change in an extending direction of the fifth guide rail  4313  by controlling the position of the fixing block on the fifth guide rail  4313 , such that a light source of the optical assembly  430  can be adjusted in multiple degrees of freedom by means of the movable connector  431 . 
     In the embodiment, the light emitting device  432  is connected to the bearing member  410  by means of the movable connector  431 , and the movable connector  431  can be adjusted according to a curing effect of the printing materials, such that the light emitting direction of the light emitting device  432  is adjusted, and the curing effect of the printing materials on the printing platform  200  by the optical assembly  430  is thus improved. 
     As shown in  FIG.  2   , the printing bracket  300  includes a first guide rail  310 , a fixing seat  320  and a second guide rail  330 . 
     The first guide rail  310  is fixedly arranged on the base  100 , the first guide rail  310  is provided with a first sliding groove  311  extending in a lengthwise direction of the first guide rail  310 , and the printing platform  200  is connected to the first sliding groove  311 . 
     The fixing seat  320  is fixedly and perpendicularly arranged on the base  100 . 
     The second guide rail  330  is fixedly arranged on the fixing seat  320 , the second guide rail  330  is arranged perpendicular to the first guide rail  310 , the second guide rail  330  is provided with a second sliding groove  331  extending in a lengthwise direction of the second guide rail  330 , and the printing head assembly  400  is connected to the second sliding groove  331 . 
     The first guide rail  310  and the second guide rail  330  can be made of guide rail profiles, which have high straightness and are firm and reliable, a sliding wheel can be fixedly provided on the surface of the printing platform  200  opposite to the base  100 , the sliding wheel is arranged in the first sliding groove  311  in a rolling manner, and when the printing platform  200  slides relative to the first guide rail  310 , the sliding wheel rolls in the first sliding groove  311 , and the printing head assembly  400  can also be connected to the second sliding groove  331  by means of the same principle. 
     Specifically, as shown in  FIG.  2   , the fixing seat  320  includes two supporting legs  321 . The two supporting legs  321  are fixedly arranged on the base  100  at an interval, and a position of the first guide rail  310  on the base  100  partially overlaps a spacing between the two supporting legs  321  on the base  100 . 
     In the embodiment, the first guide rail  310  is fixedly arranged on the base  100 , the first guide rail  310  is provided with the first sliding groove  311  extending in the lengthwise direction of the first guide rail  310 , and the printing platform  200  is connected to the first sliding groove  311 , to implement a movement of the printing platform  200  in the lengthwise direction of the first guide rail  310 ; the fixing seat  320  is fixedly and perpendicularly arranged on the base  100 ; and the second guide rail  330  is fixedly arranged on the fixing seat  320 , the second guide rail  330  is arranged perpendicular to the first guide rail  310 , the second guide rail  330  is provided with the second sliding groove  331  extending in the lengthwise direction of the second guide rail  330 , and the printing head assembly  400  is connected to the second sliding groove  331 , to implement a movement of the printing head assembly  400  in the lengthwise direction of the second guide rail  330 . 
     In addition, a platform fixing seat  700  can be provided at a bottom of the printing platform  200 , a fourth through hole  710  is provided in the platform fixing seat  700 , a micrometer head  800  penetrates the fourth through hole  710  and abuts against the printing platform  200 , so as to level the printing platform  200 , and leveling precision of the printing platform  200  can be improved by adjusting the micrometer head  800 . 
     As shown in  FIG.  2   , the printing head assembly  400  further includes a third guide rail  440 . The third guide rail  440  is arranged perpendicular to the second guide rail 
     The third guide rail  440  is provided with a third sliding groove  441  extending in a lengthwise direction of the third guide rail  440 , and the bearing member  410  is connected to the third sliding groove  441 . 
     It should be understand that the third guide rail  440  can be also made of a guide rail profile, a sliding wheel is provided on the surface of the bearing member  410  opposite to the third sliding groove  441 , and the sliding wheel rolls in the third sliding groove  441 , to movably connect the bearing member  410  to the third sliding groove  441 . 
     Moreover, the third guide rail  440  is arranged perpendicular to the second guide rail  330 , and the second guide rail  330  is arranged perpendicular to the first guide rail  310 . That is, the first guide rail  310 , the second guide rail  330 , and the third guide rail  440  serve as an X axis, a Y axis, and a Z axis of the printing device, respectively, thereby implementing three-dimensional printing of the printing device. 
     As shown in  FIGS.  1  to  4   , an embodiment of the present application provides a printing device. The printing device includes a base  100 , a printing platform  200 , a printing bracket  300  and a printing head assembly  400 . 
     The printing platform  200  is connected to the base  100 . 
     The printing bracket  300  is fixed on the base  100 . 
     The printing head assembly  400  is connected to the printing bracket  300  and is arranged above the printing platform  200 . The printing head assembly  400  includes a bearing member  410 , a discharging assembly  420  and an optical assembly  430 . The discharging assembly  420  and the optical assembly  430  are both arranged on the bearing member  410 , the discharging assembly  420  is used for providing printing materials of at least two colors for the printing platform  200 , and the optical assembly  430  is used for curing the printing materials on the printing platform  200 . 
     Further, the discharging assembly  420  includes at least two storage boxes  421 . The at least two storage boxes  421  are used for storing printing materials of different colors. 
     The nozzle assemblies are provided on the side of the storage boxes  421  opposite to the printing platform  200 , and is used for jetting the printing material to the printing platform  200 . 
     Further, feeding ports  4211  are also provided on the storage boxes  421 , and the feeding ports  4211  are used for adding the printing material into the storage box  421 . 
     Further, the printing device further includes a light shielding member  500 . The light shielding member  500  is movably arranged between the nozzle assemblies and the printing platform  200 , so as to switch the nozzle assemblies between a state in which the nozzle assemblies are shielded by the light shielding member  500  and a state in which the nozzle assemblies are not shielded by the light shielding member  500 . 
     Further, at least two first through holes  510  are provided in the light shielding member  500  at intervals. 
     In the state in which the nozzle assemblies are not shielded by the light shielding member  500 , the at least two first through holes  510  are respectively located at vertical projection positions of the nozzle assemblies of the at least two storage boxes  421  on the light shielding member  500 . 
     In the state in which the nozzle assemblies are shielded by the light shielding member  500 , positions of the at least two first through holes  510  do not overlap the vertical projection positions of the nozzle assemblies of the at least two storage boxes  421  on the light shielding member  500 . 
     Further, the printing device further includes a driving assembly  600 . The driving assembly  600  includes a closed synchronous belt  610 , a driving mechanism  620  and a synchronous wheel  630 . The closed synchronous belt  610  is connected to the light shielding member  500 , an output shaft  621  of the driving mechanism  620  is located at a first end of the closed synchronous belt  610 , the output shaft  621  is connected to the closed synchronous belt  610 , the synchronous wheel  630  is located at a second end of the closed synchronous belt  610  opposite to the first end, and the synchronous wheel  630  is connected to the closed synchronous belt  610 . 
     The driving mechanism  620  is used for driving the output shaft  621  to rotate to drive the closed synchronous belt  610  to move, so as to drive the light shielding member  500  connected to the closed synchronous belt  610  to switch between the state in which the nozzle assemblies are shielded and the state in which the nozzle assemblies are not shielded. 
     Further, the bearing member  410  includes a first bearing plate  411  and a second bearing plate  412 . A first side of the first bearing plate  411  is perpendicularly connected to a first side of the second bearing plate  412 , the first bearing plate  411  is connected to the printing bracket  300 , and the optical assembly  430  is arranged on a second side of the second bearing plate  412  opposite to the first side. 
     A second through hole is provided in the second bearing plate  412 , and the discharging assembly  420  is used for providing the printing materials of at least two colors for the printing platform  200  by means of the second through hole. 
     Further, the optical assembly  430  includes a movable connector  431  and a light emitting device  432 . The light emitting device  432  is connected to the bearing member  410  by means of the movable connector  431 . 
     The movable connector  431  is used for adjusting a light emitting direction of the light emitting device  432 . 
     Further, the printing bracket  300  includes a first guide rail  310 , a fixing seat  320  and a second guide rail  330 . 
     The first guide rail  310  is fixedly arranged on the base  100 , the first guide rail  310  is provided with a first sliding groove  311  extending in a lengthwise direction of the first guide rail  310 , and the printing platform  200  is connected to the first sliding groove  311 . 
     The fixing seat  320  is fixedly and perpendicularly arranged on the base  100 . 
     The second guide rail  330  is fixedly arranged on the fixing seat  320 , the second guide rail  330  is arranged perpendicular to the first guide rail  310 , the second guide rail  330  is provided with a second sliding groove  331  extending in a lengthwise direction of the second guide rail  330 , and the printing head assembly  400  is connected to the second sliding groove  331 . 
     Further, the printing head assembly  400  further includes a third guide rail  440 . The third guide rail  440  is arranged perpendicular to the second guide rail  330 . 
     The third guide rail  440  is provided with a third sliding groove  441  extending in a lengthwise direction of the third guide rail  440 , and the bearing member  410  is connected to the third sliding groove  441 . 
     It should be noted that the terms “include”, “comprise”, or any other variant thereof herein is intended to encompass a non-exclusive inclusion, such that a process, method, article, or apparatus that includes a series of elements not only includes those elements, but also includes other elements not explicitly listed, or elements that are inherent to such a process, method, article, or apparatus. In the absence of more restrictions, the element defined by the phrase “including a/an . . . ” does not exclude the presence of a further identical element in the process, method, article or device that includes the element. In addition, it should be noted that the scope of the method and device in the embodiments of the present application is not limited to performing functions in order shown or discussed, but can further include performing functions in a substantially simultaneous manner or in a reverse order according to the functions involved. For example, the described method can be performed in an order different from that described, and various steps can be added, omitted, or combined. In addition, features described with reference to certain examples can be combined in other examples. 
     The embodiments of the present application are described above with reference to the accompanying drawings, but the present application is not limited to the specific embodiments described above, which are merely illustrative and not restrictive. Those skilled in the art can also make many forms in light of the present application without departing from the spirit of the present application and the scope of protection of the claims, and these forms all fall into the scope of protection of the present application.