Process for defining an array of pixels in a thin film

Abstract

A method for defining an array of light-emitting pixels in a thin film electroluminescent edge emitter structure includes the steps of moving the structure in proximity to a stationary first laser source as the first laser source is operated to generate a plurality of first laser pulses. The plurality of first laser pulses are focused into 'lines' of light energy that strike the structure at a plurality of spaced apart locations in succession to ablate a predetermined number of layers of the structure. This ablation process forms a plurality of spaced apart channels in the structure. The portions of the structure remaining between each pair of adjacent channels define an array of pixels in the structure. The structure having the pixels formed therein is moved in proximity to a second laser source. The second laser source is movable in a selected direction substantially perpendicular to the direction of movement of the structure. The second laser source provides a second laser beam that is focused to a 'point' of light energy which strikes the end portion of each pixel at an area inward of the pixel edge surface to ablate a predetermined number of layers at each pixel end portion. The movement of the second laser beam is controlled relative to the movement of the structure to correspondingly control the amount of material ablated inward of the edge surface of each pixel to remove the pixel edge surface and form a new pixel edge surface shaped to a preselected contour.