Toward better printing quality for a drop-on-demand ink-jet printer: improving performance by minimizing variations in drop properties (original) (raw)

2013, IEEE Control Systems

February 2013 « IEEE CONTROL SYSTEMS MAGAZINE 43 D rop-on-demand (DoD) ink-jet printing is an efficient technology for depositing picoliter drops on various printing surfaces. DoD technology is compatible with various liquids and does not require contacting the printing media. DoD inkjet printing combines several advantages including high speed, quiet operation, and compatibility with a variety of printing surfaces. Moreover, DoD printing can make patterns without any additional lithographic process. Ink-jet printing can reduce the number of processing steps compared to conventional patterning processes, which results in a lower production cost. Therefore, DoD ink-jet technology is applied in many engineering and scientific applications (see Figure 1), such as the formation of the conductive tracks for printed circuit boards, color filters in flat panel displays and plasma displays, polymer light-emitting diode displays, organic transistors, and the construction of DNA microarrays [1]-[5]. Faster, better printing quality, and lower manufacturing costs are the main challenges for the development of professional ink-jet printing systems. In the past decades, important technological advances in ink-jet printing have made these systems commercially available for home and office environments. Industrial developments have been constantly pushing the limits in terms of productivity, accuracy, resolution, minimizing disturbance levels, and reliability. Meeting the performance requirements is restricted by several operational issues that are associated with the design and operation of ink-jet printheads. Major technical issues that are usually encountered are residual vibrations in and crosstalk among ink channels. These issues result in jetting drops with different properties and consequently a poor printing quality for high-speed printing. Given any arbitrary bitmap, the main objective is to design actuation pulses such that variations in the velocity and volume of the jetted drops are minimized. Toward this objective, a model-based inverse feedforward approach and a model-free optimization scheme are presented in this article to improve the performance of a professional DoD ink-jet printhead by minimizing the drop properties variations.