| 摘要 |
PURPOSE:To effectively remove bubbles, dust or the like from the interior of a recording head, by discharging an ink by simultaneously driving a means for forcibly discharging the ink from the recording head and the recording head while varying a driving force for the head. CONSTITUTION:A recording operation is started by depressing a printing switch in a switch group, and a recovering operation is carried out when another switch in the switch group is depressed. An ink in a liquid passage is sucked by a pump, simultaneously when a signal is applied to a recording head driver, whereby a recording head is driven. By the driving of the head, the ink is vibrated, so that removal of minute bubbles sticking to the inner wall of the liquid passage in the head 2 and being difficult to remove is facilitated. The bubbles are removed from the liquid passage irrespective of the size of the bubbles, by driving the head while varying a driving force for the head simultaneously with forced discharge of the ink. The bubbles can be substantially completely removed, by driving an ink suction pump while performing or repeating an operation of varying the driving force for the head. |
