| 摘要 |
PROBLEM TO BE SOLVED: To assure a use in dead zones of flexible films, and to perform stable back-pressure control and liquid supply by effectively suppressing a pressure variation.SOLUTION: A supply-side pump (34) and a supply-side sub-tank (40) are arranged at a supply-side flow passage (30) supplying liquid to liquid discharge heads (12, 14), and a collection-side pump (64) and a collection-side sub-tank (70) are arranged at a collection-side flow passage (60). The respective sub-tanks (40, 70) are constituted by being divided into liquid chambers (46, 76) and gas chambers (48, 78) by flexible films (44, 74), and gas pressure detection means (110, 120) for detecting the gas pressure in the respective gas chambers are arranged. A control means (150) detects whether the flexible films (44, 74) are in motions in dead zones or in motions out of the dead zones from a relationship between pressure values of the respective gas chambers (48, 78) detected by the gas pressure detection means (110, 120) and a flow rate of liquid flowing in a circulation system. |
