| 摘要 |
PURPOSE:To control the viscosity of ink for a long period of time by such an arrangement wherein the amount of deflection of ink droplets is detected and ink droplets are spouted to a detection electrode unit for a certain length of time more than a fixed rate for the interval of correcting time, and then ink is recovered and discarded. CONSTITUTION:When an electric charge is selectively given to ink droplets from a head 1 by a charging electrode 2, ink droplets are deflected by a deflection electrode 3 and record a character, etc. on a sheet of recording paper. The amount of deflection is corrected by sending ink droplets to a deflection detection electrode 5 at the rate of once every several tens - several hundreds seconds. Ink droplets not deflected are caught by a gutter 4 and sent to a supply tank 9 by a recovery pump 8, but the viscosity of ink becomes high due to the evaporation of moisture during that time. Therefore, ink droplets from the head 1 of more than a fixed rate are not circulated and they are discarded and an amount of new ink corresponding to that of discarded ink droplets is supplied to prevent the rise of viscosity of ink. In other words, after the amount of deflection is corrected, ink droplets are spouted to the detection gutter 6, and they are deflected and recovered and discarded in a waste tank 7. To prevent the generation of mist at the gutter 6, it is desirable that angle alpha between the flying direction of ink droplets 13 and the gutter 6 be made an acute angle. |
