Patent ID: 6450601
Filing Date: 2002-09-17
Classification: B41J

Abstract:
A method of managing the ink quality in an ink jet printer, wherein information on ink pressure P, temperature T, and jet speed V, and a desired pressure value curve Pconsigne as a function of temperature T and speed V is available, of the type:Pconsigne=aÃ—&rgr;n(T)Ã—V2+bÃ—&mgr;n(T)Ã—V+&rgr;n(T)Ã—gÃ—H H being the difference in level between the print head and the pressure transducer, &rgr;n(T) and &mgr;n(T) characteristic curves of the nominal ink, a and b being characteristic values of the ink circuit and g gravity acceleration, characterized in that, when the machine is started, jet speed is varied at its nominal value and the resulting pressure P(T)=aÃ—&rgr;(T)Ã—V2+bÃ—&mgr;(T)Ã—V+&rgr;(T)Ã—gÃ—H is measured so as to determine the coefficients a, b, &rgr;(T), &mgr;(T), and H, and corrective action is taken for the ink quality to make &rgr;, &mgr;, and P close to &rgr;n, &mgr;n, and Pconsigne to the temperature T.