Patent ID: 6084605
Filing Date: 2000-07-04
Classification: B41J

Abstract:
An ink jet printer comprising:a plurality of first ink pressure chambers each holding ink, each first chamber being defined by opposed walls formed of piezoelectric material, the walls of each chamber being deformable to eject ink drops from each such first ink pressure chamber when a first voltage is applied to the walls of each respective first ink chamber during a printing operation;a second ink pressure chamber in fluid communication with each of said plurality of first ink pressure chambers and also holding ink, the second ink pressure chamber being defined by opposed walls formed of piezoelectric material, the second ink pressure chamber not ejecting ink drops during the printing operation; andan ink-state detector, producing a detection signal representing information on a state of the ink between the walls of the second ink pressure chamber as an indication of the state of the ink in each of the plurality of first ink chambers.