Ink droplet ejection device for a drop-on-demand type printer

An array of ink droplet ejection devices, comprising:

• a piezoelectric transducer having a first end and a second end and being formed with a plurality of grooves on one surface thereof, the grooves extending from the first end to the second end in parallel to one another at equally spaced intervals, each of said grooves being defined by two side walls and a bottom surface, each of said side walls having a first height and defined by side surfaces and a top surface;
• first and second electrodes separately provided on the side surfaces of each of said side walls;
• a driving unit for applying an electric field between said first and second electrodes;
• a cover plate having a first end and a second end and being formed with a plurality of grooves on one surface thereof, the grooves of said cover plate extending from the first end to the second end in parallel to one another at equally spaced intervals that are off set from those of said piezoelectric transducer to permit mating with said piezoelectric transducer, each of said grooves of said cover plate being defined by two side walls and a bottom surface, each of said side walls of said cover plate having a second height higher than the first height and being defined by side surfaces and a top surface;
• an orifice plate attached to the first end of both said piezoelectric transducer and said cover plate, said orifice plate being formed with a plurality of orifices;
• and
• an ink tank connected to the second end of both said piezoelectric transducer and said cover plate,
• wherein the groove-formed surfaces of said piezoelectric transducer and said cover plate are engaged with each other so that the side walls of said piezoelectric transducer and said cover plate are alternately arranged to form a plurality of ink channels, wherein said piezoelectric transducer and said cover plate are in surface contact with each other at the side surfaces of the respective side walls, a contacting side wall of said piezoelectric transducer being deformable to a first extent when the electric field is applied between the first and second electrodes of the contacting side wall of said piezoelectric transducer, a contacting side wall of said cover plate being deformed to a second extent greater than the first extent, and wherein each of said ink channels is defined by a side surface of the side wall of said piezoelectric transducer, a side surface of a side wall of said cover plate, and the bottom surfaces of both said piezoelectric transducer and said cover plate.