| 摘要 |
PURPOSE:To provide a device for effectively detecting the printing error of an on-demand type ink jet printer without visual observation having charging electrodes, a receiving electrode, a detector for detecting the arrival of charged ink particles to the receiving electrode. CONSTITUTION:Charging electrodes 2, 2, to which a high voltage is applied from a DC power source 5 are provided at an inlet of a ?-shaped base stand 1 formed with an electrostatic shielding member 9, a receiving electrode 7 is provided on the bottom of the base 1, and a channel error detector is formed by connecting a detector (having a charging circuit 12, a differentiating circuit 13 and an amplifier 14) 8 to the electrode 7. A printing head 3 is moved to the channel error detecting position facing the detector, ink particles are then sequentially injected from all the nozzles 4, are charged by the electrodes 2 and are collided to the electrode 7. Accordingly, pulse signals of the prescribed interval are generated in the detector 8, but when the signals are missing, the channel error is detected. |
