Method for removing air bubbles or solid impurities from the printing head of a drop-on-demand type ink jet printer

摘要

An ink jet printer wherein a mechanical vibration is applied by an electromechanical transducer secured to a printing head to the ink in a nozzle and a pressure chamber of the printing head when the ink jet printer is not in a printing operation state, so that an ink flow is formed in the ink passage within the period of time including the mechanical vibrating operation or after the completion of the mechanical vibrating operation. The electromechanical transducer is used when droplets are jetted out. An electromechanical transducer which is brought into contact with the printing head only when the mechanical vibration is generated can be employed. The nozzle can be covered with a liquid within the period of time including the whole of the mechanical vibrating operation.