| 摘要 |
PROBLEM TO BE SOLVED: To restrain breakage of a meniscus of ink in a nozzle.SOLUTION: A common air chamber 21 is connected to an air layer of a pressure tank 11 and an air layer of a negative pressure tank 14. A pressure side communication valve 22 opens-closes an air flow passage in an air conduit 29 between the pressure tank 11 and the common air chamber 21. A negative pressure side communication valve 23 opens-closes an air flow passage in an air conduit 30 between the negative pressure tank 14 and the common air chamber 21. A negative pressure tank atmospheric opening valve 24 is switched between a state of being cut off from the atmosphere and a state of communicating with the atmosphere. The pressure side communication valve 22 and the negative pressure tank atmospheric opening valve 24 are a normal opening type of closing during electric conduction and opening during non-electric conduction. The negative pressure side communication valve 23 is a normal close type of opening during electric conduction and closing during non-electric conduction. Nozzle pressure of an inkjet head 2 becomes meniscus breakage pressure or less during non-electric conduction.SELECTED DRAWING: Figure 1 |
