An ink jet recording apparatus comprises an ink jet head having an ink path communicating with a discharge opening for discharging ink; electrodes arranged in said ink path; a residual ink quantity detection means for detecting residual ink quantity in said ink path in accordance with a resistance value,...http://www.google.fr/patents/US5162817?utm_source=gb-gplus-shareBrevet US5162817 - Ink jet with residual ink detection that compensates for different ink properties
Ink jet with residual ink detection that compensates for different ink ...
