Impedance Matched DOD Printhead Channel
Original Publication Date: 1986-Dec-01
Included in the Prior Art Database: 2005-Mar-09
To achieve good print quality at high frequencies of operation, e.g., 10 KHz, a drop-on-demand (DOD) printhead must be designed such that the "reflection history" within the printhead is minimized. Internal reflections produce resonances within the drop generator channel -- which, in turn, limit the maximum frequency of operation due to spurious drop generation. To minimize internal reflections, it is necessary to avoid mismatches in acoustical impedance within the channel or at least spread out changes in impedance. To avoid any mismatch in acoustical impedance within the channel, each material within the channel must be evaluated to either theoretically or experimentally determine the acoustical wave velocity when that material is used as a waveguide.