The nucleation and growth of a vapor bubble from superheated water is the triggering event for the eventual ejection of an ink drop in the thermal ink jet (TIJ) printing process. A high speed stroboscopic system capable of time resolving the kinetics of the nucleation process has been developed. The core of the system is a semiconductor laser and a high speed electronic driver that is used to replace the more conventional flashlamp strobe. The time resolution of the new laser strobe is < 50 ns, which is 20-40 times higher resolution than the 1-2 microsecond(s) duration of the typical flashlamp strobe. We observe site specific formation of small vapor bubbles on the surface of a TIJ heater that are stable for up to 0.5 microsecond(s) . These site-specific bubbles also play a role in the growth of the continuous vapor bubble, the expansion of which imparts the force to eject an ink drop. A model is proposed that explains these observations.

Date Published: 27 April 1995
PDF: 6 pages
Proc. SPIE 2413, Color Hard Copy and Graphic Arts IV, (27 April 1995); doi: 10.1117/12.207576

Published in SPIE Proceedings Vol. 2413:
Color Hard Copy and Graphic Arts IV
Jan Bares, Editor(s)