Koninklijke Philips Corporation N.V.

Mark Jonathan Childs

Nigel David Young

David Andrew Fish

Jason Roderick Hector

Physical barriers () are present between neighboring pixels () on a circuit substrate () of an active-matrix display device, such as an electroluminescent display formed with LEDs () of organic semiconductor materials. The invention forms at least parts of the barriers () with metal or other electrically-conductive material () that is insulated () from the LEDs but connected to the circuitry (, T, T, Tm, Tg, Ch etc.) within the substrate (). This conductive barrier material () may back up or replace, for example, matrix addressing lines () and/or form an additional component either within the pixel array or outside. The additional component comprising the conductive barrier material () is advantageously a capacitor (Ch), or an inductor (L) or transformer (W), or even an aerial.

Active matrix display devices, and their manufacture

Physical barriers () are present between neighbouring pixels () on a circuit substrate () of an active-matrix electroluminescent display device, particularly with LEDs () of organic semiconductor materials. In order to reduce parasitic capacitance in the circuit substrate, the invention forms these barriers () with metal or other electrically conductive material () that provides at least part of the signal lines () at a higher level than the circuit substrate (). This conductive barrier material () is connected to the matrix circuitry within the substrate () but is insulated () at least at the sides adjacent to the LEDs (). Preferably, an inter-capacitance guard line () is included in the circuit substrate () between the signal lines () and the circuitry in the substrate ().

Active matrix electroluminescent display devices, and their manufacture

Physical barriers () are present between neighbouring pixels () on a circuit substrate () of an active-matrix electroluminescent display device, particularly with LEDs () of organic semi conductor materials. The invention forms these barriers () with metal or other electrically-conductive material (), that is insulated () from the LEDs but connected to the circuitry within the substrate (). This conductive barrier material () backs-up or replaces at least a part of the drive supply line () to which the LEDs are connected by a drive element T. This transfers the problem of line resistance and associated voltage drop from within the circuit substrate (), where it is severely constrained, to the much freer environment of the pixel barriers () on the substrate () where the conductive barrier material () can provide much lower resistance. Very large displays can be made with low voltage drops along this composite drive supply line (). Furthermore, the structure can be optimised to form a smoothing capacitor (Cs) between this drive supply line () with its conductive barrier material () and the further supply line () of the LED upper electrodes () extending on an insulating coating () over the top of the conductive barrier material ().

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Sutton, United Kingdom

Mark Jonathan Childs