| 摘要 |
PURPOSE:To ensure that no magnetic field is generated at non-recording time, an ink is not adhered to a nozzle tip part, a magnetic powder is prevented from being precipitated and a meniscus is formed only at the time of recording, by a system wherein a coil wound around a magnetic material nozzle having a small diameter through-hole and partially immersed in a magnetic ink is connected to a power source through a switch, and the switch is turned ON and OFF according to a picture signal. CONSTITUTION:Where the switch 4 is open and no electric current is supplied to the coil 3, only the nozzle 1 is immersed in the magnetic ink 8, and the ink is not adhered to the nozzle tip part or the outer periphery of the nozzle above the liquid level L of the ink. However, the liquid level L' of the ink in the small hole 2 of the nozzle is higher than the liquid level L in the exterior of the nozzle, due to capillarity. With the switch 4 turned ON, a magnetic field is generated to magnetize the nozzle, whereby the magnetic ink is attracted. The magnetic field is generated also in the small hole of the nozzle, so that the magnetic ink is attracted upward to form a meniscus 12 at a tip part A. At the time of recording, the power source 11 is so operated that an electric field is constantly generated between the nozzle and a counter electrode, whereby the ink is instantaneously driven to fly toward a recording member 9. |
