EP1219314B1 — Liquid discharge apparatus having magnetic valve

USPTO Abstract

A liquid discharge apparatus, such as a nebulizer, discharges liquid droplets by supplying the liquid to a vibrating element having a plurality of openings. A valve between a reservoir for the liquid and the element has a tube extending toward the vibrating element. The tube has a valve seat. The tube extends through a magnetic coil in the body of the nebulizer. A ferromagnetic stopper is positioned in the tube and biased toward the valve seat. Energization of the magnetic coil lifts the stopper off the valve seat to allow liquid to flow to the vibrating element. In the alternative, the valve may be placed in the reservoir for operation by a ferromagnetic actuator. The coil may include an electrode for measuring, in conjunction with the vibrating element, an impedance indicative of the amount of liquid provided to the element. The impedance so measured may be used to control the amount of liquid supplied from the reservoir. <IMAGE>