Abstract: An electroluminescent sheet-form lamp with a main portion of a conductive layer isolated from an edge region susceptible to detrimental conductive pathways by isolation provided along at least a portion of the perimeter of the lamp as a result of removal of a preapplied conductive coating such that, at the region of the isolation, the main portion of the one conductive layer which forms the respective electrode commences at a line spaced inwardly from the outer edge of the lamp. The preapplied conductive coating material may be removed to form a line of interruption that leaves in place a narrow margin of conductive coating in the edge region which is electrically isolated from the main portion of the coating forming the first electrode. The lamp may be formed by exposing preselected portions of the preapplied conductive coating to laser radiation sufficient to remove the preselected portions and form the region of isolation.

Abstract: An electroluminescent sheet-form lamp comprising a transparent insulation layer, a transparent first conductive layer below the insulation layer forming a first electrode, a layer of phosphor material below the first conductive layer, a layer of dielectric material below the phosphor layer, a second conductive layer below the dielectric layer forming a second electrode, and electrical connection means for applying an electrical potential between the conductive layers to cause the phosphor to transmit light through the transparent conductive layer and the transparent insulation layer, one of the conductive layers having been formed as a general conductive coating preapplied over a panel of larger dimension than the lamp, from which the lamp has been cut.