| 摘要 |
PURPOSE:To improve precision of a charge drop deflection and thus to secure a high photoprint quality through detecting fluctuation of the ink drop speed and controlling ink pressure or quantity of discharge by detecting slippage from the characteristic value coping with a moderate interval of the ink drop. CONSTITUTION:Against the flying period T of discharge drop group and non-discharge drop group, a value in moderate intervals of the drops is assumed as L in a space distance between the two points whereat the positive differential coefficient of a discharge induced to the electrode arranged isolatedly becomes maximum and the negative differential coefficient becomes maximum. Two pairs of detection electrodes 4 are arranged in the intervals L-DELTAL, L+DELTAL, and each output is put in differential amplifiers AMP1 and AMP2. Levels of each output V01 and V02 are compared to determine whether or not drop intervals are moderate, and thus incoming noises are cancelled. Further a fluctuation of the drop interval proportional to the flying speed is detected to either control the quantity of drop charges or control the ink pressure, thereby keeping the drop flying speed constant to better precision of the deflection. |
