Patent ID: 7784712

Claim:
A micro-droplet generator, comprising: a main body, having an inside with a chamber accommodating liquid to be sprayed and a lateral opening allowing liquid in said chamber to flow out; a spraying plate, placed on said main body at said opening thereof and having a center and a plurality of spraying holes in a dense arrangement around the center as well as an inner side and an outer side, wherein the inner side is facing said chamber which contacts liquid in said chamber, and the outer side is facing away from said chamber; a piezoelectric element, glued on the outer side of said spraying plate and driving vibrations thereof; and a substantially solid projection body, fixed to an inside surface of said chamber and extending into the midst of the liquid in the center of said chamber relative to said spraying plate so as to be aligned with said spraying holes, said substantially solid projection body having a planar outer surface parallel to said inner side of said spraying plate and directly opposite to the center of said spraying plate and said spraying holes of said spraying plate in a direction perpendicular to the planar outer surface, and separated by a narrow space from said inner side of said spraying plate; wherein the narrow space upon said vibrations of said spraying plate has a varying width, upon becoming wider sucking in liquid from said chamber, and upon becoming narrower pressing out liquid through said spraying holes, so that effective spraying of liquid is performed.