An apparatus for liquid-jet recording comprises an electro-thermal transducer and discharge openings for jetting a liquid by thermal action of the electrothermal transducer. The electro-thermal transducer is connected directly to a lower potential side of a power source and is connected to a higher potential...http://www.google.de/patents/US5150129?utm_source=gb-gplus-sharePatent US5150129 - Liquid jet recording method and apparatus having electro-thermal transducer connected to a higher power source potential side through a switch
