In the small color printer market, long life of print heads is a key factor to realize running cost reduction and a non-disposable engine for environment-friendly use. In the Thermal Ink Jet (TIJ) printers, kogation of ink components onto the heater due to thermal cycle caused shorter life of the heads.To solve this problem, we studied a removal method of kogation by a drive pulse called a “Recovery Pulse” which is different from that for printing. As the result, we have found that kogation can be removed efficiently from the heater by adding the recovery pulses with smaller drive energy than that for normal printing. That is, apparently this recovery is made not by a cavitation induced self-healing, but by the mechanism of residue floating or detachment. Based on the study, it can be concluded that the recovery pulse using the mechanism is effective for removal of kogation.Subsequently, we have developed a system to utilize the recovery pulses in the maintenance operations effectively and vary the drive method of print heads depending on the print history (aging). As the result, we have realized a non-disposable TIJ print head using water fast inks.
N. Morita, K. Onishi, M. Hiratsuka, M. Kobayashi, H. Tamura, "Long-Stable Jetting on Thermal Ink Jet Printers" in Proc. IS&T Int'l Conf. on Digital Printing Technologies (NIP14), 1998, pp 19 - 22, https://doi.org/10.2352/ISSN.2169-4451.1998.14.1.art00005_1