Abstract:
An important factor in quality of printing with an ink jet printing apparatus is the velocity of the ink jet stream. The present case describes a number of servo systems for controlling velocity of the stream. This can be done indirectly by sensing pressure and/or temperature or directly by sensing velocity of the stream and controlling the pump frequency or pump drive currents.
Abstract:
The present case concerns various techniques for increasing the printing rate of an ink jet printing apparatus. As one example, drops not required for printing, that is, drop intervals, are skipped. This reduces the time required to form individual characters. Another technique modifies the normal generation of drops which is sequential in a column by column fashion and instead imposes non-sequential drop generation and deflection thereby reducing drop merging and splatter that otherwise might occur.