There is disclosed an ink jet printer of Hertz type. An ink jet is continuously forced out from a nozzle and broken into minute droplets. The droplets are selectively charged by applying pulse voltage. A row of charged droplets is removed and a row of uncharged droplets proceeds to the record medium...http://www.google.es/patents/US4673951?utm_source=gb-gplus-sharePatente US4673951 - Tone reproducible ink jet printer
