| 摘要 |
PURPOSE:To prevent injection failure of ink jet or the entry of air bubbles causing the decrease in injection performance by beforehand detecting the small bubbles produced in ink passageway and effectively removing these. CONSTITUTION:The ink coming to inlet 53 through ink tube from an ink tank 38 passes through a small orifice 42 and is sent out from outlet 54 toward a filter 33. On the other hand, when many of the air bubbles 52 in the ink are captured, the buoyancy of the air bubbles 52 overcome the weight of a trap 41. The air bubble trap 41 then begins to float vertically. When the air bubbles 52 accumulate and a dielectric plate 48 comes to the dotted line position 51, the capacitance between electrode plates 35 changes and this is detected with a detector to turn OFF the driving of a head 31 or announce the same with a warning lamp, buzzer or the like. The air bubbles 52 having accumulated are recovered from an air bubble vent tube 36 with a syringe or the like, whereby the entry of the air bubbles in the head is prevented. |
