摘要 |
An ink jet printer includes a deflection electrode for providing a deflection field, which field will deflect charged ink drops. The power supply and control circuit for the deflection electrode includes a capacitor storage arrangement in which a brief short between the deflection electrode and adjacent structure will be compensated by a capacitance which is switched into electrical connection with the deflection electrode only during deflection electrode shorts. The control circuit also monitors the deflection electrode potential and if an electrode short which reduces the electrode potential substantially persists for a period greater than a preselected period of time, the printer will be disabled and printing operations terminated. |