There are many technical challenges to developing and manufacturing a piezo-based printhead for industrial applications. Velocity uniformity has an impact on image quality. Velocity uniformity refers to the variation of drop velocity from jet to jet across an individual printhead. Drop placement in the process direction impacts by drop velocity variation, which results in time-of-flight errors. Previous Spectra presentations have reviewed, in detail, the mechanisms of crosstalk. Crosstalk is the measure of the mechanical, fluidic and electrical interactions between components within a printhead and results in drop mass and velocity variation. Often, crosstalk is most notable between neighboring jets. Variations in drop mass and velocity can have a negative impact on image quality. Excessive crosstalk can even lead to jet decay and outage. The frequency response of a printhead is also an important parameter and must be understood. Printhead average drop velocity and mass will often change as a function of the operating frequency. In addition, crosstalk is not usually constant throughout the operating frequency range for any given printhead design.This paper presents data of frequency response, velocity uniformity, and crosstalk. Spectra has developed technology to improve printhead performance relative to crosstalk, frequency response, and velocity uniformity. Results from testing of piezo based printheads manufactured for use in the case coding market will be discussed to demonstrate the performance enhancements and the impact on image quality.
Thomas G. Duby, "Performance Improvements for Commercial Piezo Printhead" in Proc. IS&T Int'l Conf. on Digital Printing Technologies (NIP17), 2001, pp 328 - 331, https://doi.org/10.2352/ISSN.2169-4451.2001.17.1.art00072_1