| 摘要 |
PURPOSE:To enable a nozzle of a recording head to be speedily recovered into a normal jetting condition, by gradually decreasing oscillating energy when removing bubbles, foreign matter or the like present in an ink passage by vibrating an ink. CONSTITUTION:When an abnormal jetting is found in the nozzle of the recording head, a purging operation is started. Concurrently with the purging operation, a channel associated with the nozzle in which defective jetting is found is driven to vibrate. In an example of a signal waveform of a vibration-driving signal, an integrated waveform of a rectangular wave is provided in the period from point F to point G, and then the voltage is gradually lowered exponentially to point J. With the vibration-driving impressed energy (y) thus gradually reduced, a normal-condition rate (z) is gradually varied from point C to point D which corresponds to a normal-condition rate of 100%. Alternatively, when gradually reducing the impressed energy (y), it is repeatedly increased and decreased in a sawtooth form to gradually reduce it to an envelope (a) of increase peak values G, G1, G2...G7-H. |
