Method of locating common electrode shorts in an imager assembly

Abstract

A process for locating common electrode shorts in an electronic array, such as an x- y- addressed imager assembly having a short circuit between an address line and an overlying common electrode layer, includes the steps of applying a test voltage to the addressed line shorted to the common electrode, measuring current at each of a plurality of common electrode contact points disposed at selected intervals along selected edges of the common electrode, and processing the respective measured currents in accordance with a selected relationship to localize a short circuit location along the length of the shorted address line. In imager assembly arrangements in which it is possible to measure currents on opposite sides of the common electrode disposed substantially perpendicular to the orientation of the shorted address line, the selected relationship is I.sub.A-N /I.sub.a-n =(L-X)/X, wherein: I.sub.A-N are the measured currents from common electrode contact points along one common electrode opposite edge; I.sub.a-n are the measured currents from common electrode contact points along the the other common electrode opposite edge; L represents the length of the shorted address line; and X represents the point of the short circuit as distance from the common electrode first opposite edge. An x- y- addressed imager assembly adapted for use of this method includes a common electrode having more than two electrical contact points disposed at selected intervals along each edge of the common electrode that corresponds to a lateral boundary of the imager assembly.