| 摘要 |
PURPOSE:To detect the place of bubble formation and to efficiently remove the bubbles by a method wherein a detection control means inputting output signals from a piezolelctric element is provided, and monitoring is made therewith either on the duration of periodic damping or on the amplitude of peak values of the output signals from the piezoelectric element to find out whether the bubbles are existent in a pressuer chamber or in an ink chamber. CONSTITUTION:A detection control means 11 is able to detect whether bubbles are formed or not and whether the formation is in a pressure chamber 2 or in an ink chamber 3 by monitoring at least one of the following two: the amplitude of peak values and the time of periodic damping of output voltage of a piezoelectric element 7. When the detection control means 11 detects the formation of the bubbles, printing is stopped and the formation is judged whether it is made in the ink chamber 3. In the case where the formation is made in the ink amber 3, a purge pump 10 is operated under 0.1kg/cm<2> pressure for 5 seconds. In the case where the bubbles are formed in the pressure chamber 2, not in the ink chamber 3, the purge pump 10 is operated under 0.2kg/cm<2> pressure for 10 seconds. |
