| 摘要 |
PURPOSE:To shorten the trailing time of DC voltage to be applied by a method in which a charge circuit by which charge pulse voltage for recording is applied to charging electrode during printing and a lapped voltage consisting of DC voltage and pulse for detecting phase is applied to the charging electrode during detection of ink droplets-cutting phase is provided, and a resistor for discharging is inserted through a switch into the output terminal of the charging circuit. CONSTITUTION:Printing signal or phase detection signal is applied to the base of a transistor Tr1 and amplified. During the printing period, the printing signal is sent out by clamping the positive side to earthing potential by a condenser C, a resistor R, and diode D1. During detection of phase, since signal SIG1 becomes of low level, transistors Tr2 and Tr3 are turned ON, output voltage V0 to be applied to the charging electrode is clamped to -VDC and lapped with charge pulse for detecting phase, and phase detection is performed. In conjunc tion with a timing that Tr3 is turned OFF, signal SIG2 is applied, the transistor TR4 is turned ON, and charge of the condenser C is discharged through the resistor R2. If R2<<R1 holds in this case, the trailing of output V0 can be acceler ated. |
