A light-emitting-diode array is formed on a substrate having an upper layer of a semiconducting material and a lower layer of an insulating or semi-insulating material. The upper layer is divided into blocks by isolation channels that cut completely through the upper layer. The light-emitting diodes, which are formed by selective diffusion of an impurity into the upper layer, are arranged in a single row, with at least two light-emitting diodes in each block of the upper layer. Each block has a block electrode that drives the light-emitting diodes in the block. The row of light-emitting diodes is paralleled by a number of shared lines which cross the isolation channels. Each shared line is coupled to a plurality of light-emitting diodes in different blocks.