| 摘要 |
PURPOSE:To prevent a nozzle from being clogged by such an arrangement wherein the formation of a protective film of magnetic fluid is released as the magnetic fluid is attracted and held by an electromagnet to which a current is supplied at the time of printing operation of a printer and a protective film which shuts off the orifice of the nozzle from the open air is formed by stopping the supply of electricity when the printer is not operated. CONSTITUTION:A dry-up preventing device of this invention is composed of an electromagnet 26 which is arranged between an orifice 3A of a nozzle 3 and an electrode 5 for charging and positioned close to the surface of the orifice 3A and has a passage 25 of an ink flow spouted from the orifice 3A and a magnetic fluid 27 which is held at the side of the passage 25 of the electromagnet 26 and forms a protective film. At the time of printing, the fluid 27 is attracted and held by the electromagnet to which a current is supplied and the orifice 3A of the nozzle 3 is exposed to the open air. Printing is properly carried out by a flow of ink particles spouted from the orifice 3A through the passage 25, the electrode 5 and a deflection plate. When the printer is not operated, the fluid 27 is released from the electromagnet 26 as the supply of electricity thereto is cut off and a film for shutting off the orifice 3A of the nozzle 3 from the open air is formed by the surface tension of the fluid 27 and it prevents the nozzle 3 from drying up. |
