Methods of detecting and adjusting contact of a micro-structural fluid ejector to a substrate and method of detecting a fault condition in fluid flow from a micro-structural fluid ejector onto a substrate

Abstract

Methods are disclosed relating to the operation of a micro-structural fluid ejector in a fluid printing apparatus. The methods include providing an imaging system, capturing a digital image of the micro-structural fluid ejector and its surroundings, and pre-processing the digital image to detect edges. A method of detecting contact of a micro-structural fluid ejector to a substrate includes repeatedly lowering the print head and measuring the length of a detected edge until the currently measured length is determined to be longer than a previously measured length. A method of adjusting contact of a micro-structural fluid ejector to a substrate includes calculating a bending coefficient A of the micro-structural fluid ejector and lowering the print head toward the substrate if the bending coefficient A is less than a minimum threshold value A, raising the print head away from the substrate if the bending coefficient A is greater than a maximum threshold value A, and making no change to the vertical displacement of the print head if the bending coefficient A is in the range of Ato A. A method of detecting a fault condition in fluid flow from a micro-structural fluid ejector onto a substrate includes analyzing the digital image to determine whether edges are present in a region of interest where fluid dispensed from the micro-structural fluid ejector should be present.