| 摘要 |
PURPOSE:To detect the presence or absence of the injection of ink droplets with a high accuracy by a simplified method in which the electrical change in a material to which ink droplets are adhered is detected. CONSTITUTION:Charged ink droplets 11 to be injected from a nozzle 13 are adhered to a conductive material 27 connected to the earth through a resistor 28, and the voltage produced by the adherence of ink droplets is compared with a reference voltage 30 by a comparator 29. When the compared result is above a fixed value, it is regarded that charged ink droplets are adhered to the material 27 and logical ''1'' is sent out to the upper order device (a) which makes a judgement that ink droplets are injected from the nozzle when the logical ''1'' is put in the device. |
