Ink droplet expelling apparatus

DETAILED DESCRIPTION An object of the present invention is to solve the foregoing problems in the conventional ink droplet expelling apparatus having a simple arrangement.
Another object of the present invention is to provide an ink droplet expelling apparatus in which an ink droplet can be expelled at a high expelling speed, and the ink droplet can be stably expelled in accordance with a higher driving frequency.
In order to solve the foregoing problems in the prior art so that an ink droplet can be expelled at a high speed and driving can be made with a higher frequency, conditions are required for the ink droplet expelling apparatus in the following three points or operations: (1) Acceleration of an ink flow to expel an ink droplet out of the nozzle at a sufficient speed; (2) Reduction in pressure in the ink chamber at suitable timing for separating an ink droplet from the ink in the ink chamber; and (3) Suppression of pressure fluctuation in the ink chamber immediately after ink droplet expelling, and supplement of ink required for the next ink droplet.
In order to satisfy these conditions, in the ink droplet expelling apparatus according to the present invention, the three operations as described above are separately controlled in accordance with individual driving signals.
The above and other objects, features, and advantages of the present invention will be apparent from the following detailed description taken in conjunction with the accompanying drawings.