| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem in which: in an ink jet printer, the ink discharge amount during the execution of pressure purge needs to be suppressed; in a case of having a plurality of heads with the same color, density unevenness between the plurality of heads after the purge needs to be eliminated to improve image quality; and the drawing of air bubbles has to be prevented when forming meniscus of ink in a nozzle after the purge.SOLUTION: A sub-tank 321 is pressurized by a pump 341 in a state of closing valves 313, 315. Then, purge of a head 21 is performed by opening the valve 313, and purge of a head 22 is performed by opening the valve 315 after opening the valve 313. After the purge, an atmosphere open valve 352 opens in a state of opening the valves 313, 315. Meniscus of ink is formed in the heads 21, 22 by decompressing the sub-tank 321 by a decompression pump 361 after reducing the inner pressure of the heads 21, 22, which has risen by the purge.SELECTED DRAWING: Figure 4 |
