Patent ID: 7207651

Claim:
An acoustic inkjet printing apparatus, the acoustic inkjet printing apparatus comprising: a printing liquid containing chamber containing a printing liquid; a piezoelectric element including a main transducer and a sub transducer provided on at least one side of the main transducer, the piezoelectric element receiving a drive signal and generating an acoustic wave in response to receiving the drive signal; an acoustic focusing member focusing the acoustic wave generated by the piezoelectric element near the surface of the printing liquid, thereby ejecting droplets of the printing liquid; a droplet recovery member provided adjacent to the printing liquid containing chamber, such that the droplet recovery member is in contact with the surface of the printing liquid contained within the printing liquid containing chamber and facing toward the surface of the printing liquid, the droplet recovery member having an opening, through which some of the ejected droplets pass, and a droplet recovery surface facing toward the surface of the printing liquid, such that other ejected droplets that do not pass through the opening hit the droplet recovery surface and are returned to the printing liquid containing chamber; and the acoustic inkjet printing apparatus being capable of switching between a first ejection mode in which the ejected droplets are ejected in a first direction perpendicular to the surface of the printing liquid in the printing liquid containing chamber and a second ejection mode in which the ejected droplets are ejected at an angle to the first direction by applying or not applying a drive signal to the sub transducer in accordance with image printing data, while a drive signal is being applied to the main transducer of the piezoelectric element.