| 摘要 |
PURPOSE:To carry out phase control strong in a cutting phase due to the change in an environmental condition and having reliability, by carrying out reference successively from the opposite phase of the previous stored phase when the phase of a charging pulse to ink droplets is referred. CONSTITUTION:An oscillator 7 supplies a clock pulse to an oscillating circuit 9 which in turn applies a sine wave signal to a head to carry out the oscillation thereof. A test charging pulse having frequency same to that of the sine wave signal and having predetermined phase relation thereto is generated by a phase control circuit 8 and a charging circuit 10 to be applied to a charging electrode 3. A detecting circuit 11 detects whether ink droplets caught by a gutter 6 are charged or not and, by the detected output, the circuit 8 is controlled to control the phase of the charging pulse to carry out printing in an optimum phase by the charging pulse. In this case, the circuit 8 stores the charging phase detected by the previous phase reference and successively carries out reference from the opposed phase of the previously stored phase when the phase is referred. |
