In continuous ink jet printing, ink is supplied under pressure to a manifold region that distributes the ink to a plurality of orifices, typically arranged in a linear array(s). The ink discharges from the orifices in filaments which break into droplet streams. The approach for printing with these droplet streams is to selectively charge and deflect certain drops from their normal trajectories. Graphic reproduction is accomplished by selectively charging and deflecting drops from the drop streams and depositing at least some of the drops on a print receiving medium while other of the drops strike a drop catcher device. The continuous stream ink jet printing process is described, for example, in U.S. Pat. Nos. 4,255,754; 4,698,123 and 4,751,517, the disclosures of each of which are totally incorporated herein by reference.
As ink jet printer systems grow increasingly more complex and the types, colors and variety of inks used in such systems increase, the control and configuration of the electro-mechanical systems of the ink jet printer for particular applications grows more difficult. To this end, commonly assigned, co-pending patent application Ser. No. 08/810,653, provided provision for the ink-jet printer to self configure itself to optimize the operability of the printer based on the ink used and the assembled printhead characteristics. The printer used a combination of matrices to store data specific for the ink used and data specific to the assembled printhead. These ink jet characteristics are stored in the computer memory, to be accessed for customized operation and configuration. If, for example, the operator changes the ink in the system, the operator indicates this to the computer. The ink jet characteristics stored in the computer are then accessed to optimize a whole new set of ink jet operating parameters based on the new ink. The computer, rather than the operator, causes printer timing, ink pressures, temperature compensations, and any other operating parameters to be changed to optimize the printer operation. Hence, the computer interprets the matrixed information to optimize operation of the ink jet printing system.
Such a system has been found to work effectively to allow the printer to operate with a wide variety of inks without the need for the operator to manually adjust the various operating parameters. It has been found that while this prior art did make the printer more user friendly, the printer was still deficient. While it has been well know that different inks require the use of different values for parameters related to flow out of the orifices and for drop break off to make the system operable, it had not been understood that there exist other operating parameters which affect not so much operability as reliability. As a result different inks could both be operated at their optimum operating points for operability but still have quite different reliability characteristics. These reliability characteristics include but are not limited to the effect the ink or other fluids may have on component performance, wear-out or failure.
What is needed, therefore, is a means to ensure that not only operability but reliability can be maintained at optimal levels.