Abstract:
The present invention relates to a nozzle plate structure which comprises a plate and a plurality of orifices penetrating the plate. Each orifice comprises a liquid-storing space and a liquid-outputting space. Through the configuration of the liquid-storing space, the liquid in a container can be smoothly educed therefrom. Through the configuration of the liquid-outputting space, liquid dripping can be decreased. Alternatively, a liquid-guiding space is arranged between the liquid-storing space and the liquid-outputting space, so that the resonance oscillation of the liquid in the orifice can be enhanced. Further, the remaining liquid in the liquid-outputting space can be reabsorbed by the capillarity of the liquid-guiding space.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a nozzle plate structure, particularly to a micro nozzle plate fabricated by electroforming and applied to liquid atomization devices, such as a semiconductor photoresist coating machine, a medication device, and an aromatic essential oil diffuser. Each orifice of the nozzle plate of the present invention has a structure with different layers/sections/parts/spaces so as to enhance the effect of liquid atomization. 
     2. Description of the Prior Art 
     Nozzle plates are commonly used in liquid atomization devices, such as semiconductor photoresist coating machines, medication devices, aromatic essential oil diffusers, sprayers, ink cartridges and the like. A nozzle plate uses the principle of electronic oscillation to generate high frequency vibrations to scatter a bigger molecular cluster of liquid into several smaller molecular clusters in a conditions adapted to be atomized or sprayed. 
     However, the nozzle plate structures of the current atomization devices are usually too simple to atomize liquid completely. For example, the orifice thereof is merely a circular through-hole. In such a case, liquid are likely to accumulate around the orifices, and liquid droplets are likely to drip down therefrom. Thus, the effect of atomization or the quality of spray-dispersing is degraded. 
     The present invention intends to provide a nozzle plate structure to solve the problem of droplet dripping and improve the effect and quality of liquid atomization. 
     SUMMARY OF THE INVENTION 
     In one embodiment, the present invention relates to a nozzle plate structure, which comprises a plate and a plurality of orifices penetrating the plate, wherein each orifice includes a liquid-storing space, a liquid-guiding space and a liquid-outputting space. The liquid-storing space is defined by a liquid-storing wall of the plate. The liquid-storing space has a first liquid-storing opening and a second liquid-storing opening opposite to the first liquid-storing opening. The liquid-storing wall has an arc-shaped surface. The liquid-guiding space is defined by a liquid-guiding wall of the plate. The liquid-guiding space connects and communicates with the liquid-storing space via the second liquid-storing opening. The liquid-guiding wall is smoothly connected with the liquid-storing wall. The liquid-outputting space is defined by a first liquid-outputting wall and a second liquid-outputting wall of the plate and connects and communicates with the liquid-guiding space. The first liquid-outputting wall is connected with the liquid-guiding wall. The second liquid-outputting wall is connected with the first liquid-outputting wall in a nonparallel way. 
     In another embodiment, the present invention relates to a nozzle plate structure, which comprises a plate and a plurality of orifices penetrating the plate, wherein each orifice includes a liquid-storing space and a liquid-outputting space. The liquid-storing space is defined by a liquid-storing wall of the plate. The liquid-storing space has a first liquid-storing opening and a second liquid-storing opening opposite to the first liquid-storing opening. The liquid-storing wall has an arc-shaped surface. The liquid-outputting space connects and communicates with the liquid-storing space via the second liquid-storing opening. The liquid-outputting space is defined by a first liquid-outputting wall and a second liquid-outputting wall of the plate. The first liquid-outputting wall is connected with the liquid-storing wall. The second liquid-outputting wall is connected with the first liquid-outputting wall in a nonparallel way. 
     The objective, technologies, features and advantages of the present invention will become apparent from the following description in conjunction with the accompanying drawings wherein certain embodiments of the present invention are set forth by way of illustration and example. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing conceptions and their accompanying advantages of this invention will become more readily appreciated after being better understood by referring to the following detailed description, in conjunction with the accompanying drawings, wherein: 
         FIG. 1  is a sectional view schematically showing an orifice of a nozzle plate structure according to one embodiment of the present invention; 
         FIG. 2  is a sectional view schematically showing a liquid-storing space of an orifice according to one embodiment of the present invention; 
         FIG. 3  is a sectional view schematically showing a liquid-guiding space of an orifice according to one embodiment of the present invention; 
         FIG. 4  is a sectional view schematically showing a liquid-outputting space of an orifice according to one embodiment of the present invention; 
         FIG. 5A  and  FIG. 5B  are sectional views schematically showing liquid-outputting spaces respectively having different included angles according to different examples of the present invention; and 
         FIG. 6  is a sectional view schematically showing an orifice of a nozzle plate structure according to another embodiment of the present invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The detailed explanation of the present invention is described as follows. The described preferred embodiments and examples are presented for purposes of illustrations and description, and they are not intended to limit the scope of the present invention. 
       FIG. 1  shows a sectional view of an orifice  20 A of a nozzle plate structure according to one embodiment of the present invention. The nozzle plate structure comprises a plate  10  and a plurality of orifices  20 A penetrating through the plate  10 . The orifice  20 A includes a liquid-storing space  30 , a liquid-guiding space  40  and a liquid-outputting space  50 . 
       FIG. 2  is a sectional view schematically showing the liquid-storing space  30  of the orifice  20 A according to one embodiment of the present invention. The liquid-storing space  30 , configured to be a part/space of the orifice  20 A, initially contacting with the liquid inside a container (not shown). In other words, the liquid-storing space  30  is configured to face the interior of a container. The liquid-storing space  30  is defined by a liquid-storing wall  32  of the plate  10 . The liquid-storing space  30  has a first liquid-storing opening  302  and a second liquid-storing opening  304  opposite to the first liquid-storing opening  302 . Preferably, the liquid-storing wall  32  has an arc-shaped surface. Preferably, the first liquid-storing opening  302  has a width, and the second liquid-storing opening  304  has a width D 1  smaller than the width of the first liquid-storing opening  302 . In a preferred embodiment, the liquid-storing wall  32  has an arc-shaped surface; the width of the first liquid-storing opening  302  is greater than the width D 1  of the second liquid-storing opening  304 . Preferably, the width D 1  of the second liquid-storing opening  304  ranges from 3 to 45 μm. Owing to that the liquid-storing wall  32  has an arc-shaped surface and that the width of the first liquid-storing opening  302  is greater than the width D 1  of the second liquid-storing opening  304 , the liquid in a container can easily enter the liquid-storing space  30  via the wider first liquid-storing opening  302 , and then the arc-shaped surface of the liquid-storing wall  32  smoothly guides the liquid to go out from the narrower second liquid-storing opening  304 . Such a structure favors liquid atomization or tiny-droplet formation. 
       FIG. 3  is a sectional view schematically showing a liquid-guiding space  40  of an orifice  20 A according to one embodiment of the present invention. As shown in  FIG. 1 , the liquid-guiding space  40  connects and communicates with the liquid-storing space  30  and the liquid-outputting space  50  so as to guide liquid to flow from the liquid-storing space  30  to the liquid-outputting space  50 . The liquid-guiding space  40  is defined by a liquid-guiding wall  42  of the plate  10  and has a width D 2 . The liquid-guiding space  40  connects and communicates with the liquid-storing space  30  via the second liquid-storing opening  304 . The liquid-guiding wall  42  is smoothly connected with the liquid-storing wall  32 . Preferably, the width D 2  of the liquid-guiding space  40  ranges from 3 to 45 μm. Preferably, the width D 2  of the liquid-guiding space  40  is generally equal to the width D 1  of the second liquid-storing opening  304 . Wherein, under such configuration and arrangement of the liquid-guiding space  40 , the liquid-guiding space  40  can generate the capillary effect so as to favor the liquid in a container flowing out from the liquid-storing space  30 . Further, the liquid-guiding space  40  can also enhance the resonance of the liquid in the liquid-guiding space  40  and improve the effect of atomization. Furthermore, the size of droplets can be controlled via adjusting the width D 2  of the liquid-guiding space  40 . Preferably, the liquid-guiding space  40  has a height T 1  ranging from 0.01 to 35 μm. 
       FIG. 4  is a sectional view schematically showing a liquid-outputting space  50  of an orifice  20 A according to one embodiment of the present invention. As shown in  FIG. 1 , the liquid-outputting space  50  is arranged in a region corresponding to the liquid-storing space  30  and connected with the liquid-guiding space  40  so as to output the atomized liquid inside a container to the exterior of the container. The liquid-outputting space  50  is defined by a first liquid-outputting wall  52  and a second liquid-outputting wall  54  of the plate  10 . The liquid-outputting space  50  connects and communicates with the liquid-guiding space  40 . The first liquid-outputting wall  52  is connected with the liquid-guiding wall  42 . The second liquid-outputting wall  54  is connected with the first liquid-outputting wall  52  in a nonparallel way. A liquid-outputting opening  502  is defined by an end of the second liquid-outputting wall  54  away from the first liquid-outputting wall  52 . Preferably, the first liquid-outputting wall  52  is connected with the second liquid-outputting wall  54  by an included angle θ within the liquid-outputting space  50 . Preferably, the liquid-outputting space  50  has a height T 2  ranging from 0.01 to 25 μm. The junction of the first liquid-outputting wall  52  and the second liquid-outputting wall  54  defines a width D 3  of the liquid-outputting space  50 . Preferably, the width D 3  ranges from 15 to 80 μm. Wherein, under such configuration and arrangement of the liquid-outputting space  50 , the liquid-outputting space  50  can accumulate and accommodate the atomized liquid that does not effuse/spray out. Based on the communication between the liquid-outputting space  50  and the liquid-guiding space  40 , the liquid accumulated within the liquid-outputting space  50  is reabsorbed into the liquid-guiding space  40  or the liquid-storing space  30  by the capillary effect of the liquid-guiding space  40 . Thereby, liquid-outputting space  50  can hold the accumulated liquid and prevent the accumulated liquid from dripping down. 
     Preferably, as the examples shown in  FIGS. 5A-5B , the included angle θ between the first liquid-outputting wall  52  and the second liquid-outputting wall  54  is a specified angle. That is to say, the included angle θ is a fixed angle. Wherein, the included angle θ ranges from 45 to 165 degrees, so that the second liquid-outputting wall  54  is symmetrically arranged in the cross section thereof. In  FIG. 5A , the included angle θ is an acute one, and the liquid-outputting space  50  has a liquid-outputting opening  502  narrower than that in  FIG. 4 , whereby the spray of the atomized liquid generated by the nozzle plate of the this example is more convergent, and whereby the liquid-holding effect of the liquid-outputting space  50  is further enhanced. In  FIG. 5B , the included angle θ is an obtuse one, and the liquid-outputting space  50  has a liquid-outputting opening  502  wider than that in  FIG. 4 , whereby the spray of the atomized liquid generated by the nozzle plate of this example is more divergent, and whereby the liquid-holding effect of the liquid-outputting space  50  is also enhanced. Further, the volume of the liquid-outputting space  50  is increased to accommodate more liquid, so that the nozzle plate structure this example can effectively decrease liquid dripping during a long cycle of spraying. Optionally, in an alternative example, the included angle θ between the first liquid-outputting wall  52  and the second liquid-outputting wall  54  is not a specified angle. That is to say, the included angle θ is a variable angle. Wherein, the included angle θ ranges from 45 to 165 degrees, so that the second liquid-outputting wall  54  is asymmetrically arranged in the cross section thereof (not shown), whereby the nozzle plate structure of the alternative example can also decrease liquid dripping and spray the atomized liquid to a specified direction. 
       FIG. 6  is a sectional view of a nozzle plate structure according to another embodiment of the present invention and schematically shows the structure of an orifice  20 B in a plate  10 . The orifice  20 B includes a liquid-storing space  30  and a liquid-outputting space  50 . In this embodiment, the liquid-outputting space  50  connects and communicates with the liquid-storing space  30 , and the first liquid-outputting wall  32  is connected with the liquid-storing wall  32 . More specifically, the liquid-outputting space  50  is connects and communicates with the liquid-storing space  30  via the second liquid-storing opening  304 . Wherein, the second liquid-storing opening  304  of the liquid-storing space  30  is configured to generate the capillary effect so as to guide the liquid of a container from the liquid-storing space  30  to the liquid-outputting space  50  and reabsorb the residual liquid back to the liquid-storing space  30 . The other structures and characteristics of this embodiment are similar to those of the abovementioned embodiments and examples, and hence will not repeat herein. 
     It should be noted that in the present invention, the value of each of the width D 1  of the second liquid-storing opening  304 , the width D 2  of the liquid-guiding space  40 , the width D 3  of the liquid-outputting space  50 , the height T 1  of the liquid-guiding space  40  and the height T 2  of the liquid-outputting space  50  can be adjusted by an increment or decrement of 0.01 μm. For example, the height T 1  of the liquid-guiding space  40  may have a value of 0.01 μm, 0.02 μm, 0.03 μm . . . 34.99 μm or 35 μm. In other words, the heights T 1  of the liquid-guiding space  40  are distributed in a range from 0.01 μm to 35 μm in form of an arithmetic sequence with a common difference of 0.01 μm. Similarly, the value of the included angle θ between the first liquid-outputting wall  52  and the second liquid-outputting wall  54  can be adjusted by an increment or decrement of 0.01 degrees. 
     While the invention is susceptible to various modifications and alternative forms, a specific example thereof has been shown in the drawings and is herein described in detail. It should be understood, however, that the invention is not to be limited to the particular form disclosed, but to the contrary, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the appended claims.