Ink jet printhead with ink viscosity control

摘要

In the embodiments described in the specification, an ink jet system includes an ink jet head with an ink reservoir and a passage supplying ink from the reservoir to a plurality of pressure chambers from which ink drops are ejected through a corresponding plurality of orifices, along with a viscosity-detecting arrangement for detecting the viscosity of the ink supplied to the pressure chambers and a control system for controlling a heater so as to control the temperature of the ink in order to maintain viscosity at a desired level. In a particular embodiment, the ink-viscosity detector consists of four fluidic elements having different fluidic resistance and inertance values connected in a bridge circuit which is arranged to be balanced when the ink has the desired viscosity value.