Layout structure of electrode lead wires for organic led display

#This invention relates to a layout structure of electrode lead wires for OLED display (organic light-emitting diode display), in which the internal electrodes of the display are connected to an external driving circuit via the electrode lead wires.

#As the organic light-emitting diode display (OLED display) is commented advantageous in many aspects, such as volume, weight, self-lighting, wide vision-field, high resolution, high brightness, low power-consumption, and high response-speed, therefore, it is considered a promising flat display in next generation. Many makers and research laboratories have long since focused their attention and cast efforts on this subject, however, design of an OLED display is not as easy as expected, people should consider not only power consumption and lifetime thereof but also panel disposition, etc.

#Until now, improvements have been made to power consumption and lifetime of the OLED, while, in regard with the panel design, the electrodes are distributed on sides laterally or even polygonally of a panel for the sake of solving the problem of driving voltage and power consumption of the electrodes. Nevertheless, the panel design in such a manner is defective in its structural complexity for assembling.

#The related drawings in connection with the detailed description of this invention to be made later are described briefly as follows, in which:

#FIG. 1A shows a schematic structure of a conventional OLED display;

#FIG. 1B shows a cutaway section in X-axis of the OLED display shown in FIG. 1A;

#To lay the cathode and the anode lead wires of an OLED display (organic light-emitting diode display) together on the same side of a transparent substrate of the display would probably save the construction material more or less and simplify the fabrication process to some extent however, the power consumption and the driving voltage are uplifted on the other hand according to this invention.

#In considering the situation that all the pixels are lightened at the same time, a cathode plate or pin would suffer the total current of a plurality of sub-circuit loops whereto the current from an anode is supplied, so that the current that enters the cathode is far greater than that exits the anode. Moreover, because of spatial limitation, the pin width of the cathode is narrowed to increase the impedance of its own that would inevitably uplift the power consumption as well as the driving voltage of the cathode. Besides, the impedance of the electrode lead wires will be heightened because the electrode lead wires are lengthened in the case both the cathode and the anode lead wires are arranged on the same side of the transparent substrate of the OLED display.

#Two measures might be taken to solve abovesaid problem. The first is suggested to lower down the impedance of the electrodes and lead wires thereof by using multi-layer materials (such as Cr/Al/Cr, Ti/Al/Ti) or high-conductivity metallic materials (such as Al, Ag, Au, Pd, Pt) for the electrode lead wires; and using low impedance materials having work function about the same with the OLED component layer (such as Al, Mg, Ag) for the cathode while using high permeability and low impedance materials having work function about the same with the OLED component layer (such as ITO, IZO) for the anode. The second is suggested to lay the cathode and the anode lead wires together on the side adjacent to the cathode for the reason that current is consumed mostly at the part of the cathode as well as the cathode lead wires rather than that consumed at the part of the anode and the anode lead wires as mentioned above. Therefore, to cut the cathode lead wires as short as possible will lower down its impedance for sure and reduce power consumption accordingly.