The present invention is embodied in a system and method for protecting an electronic device connected to a telephone line. The above-mentioned at least one organic layer includes a layer of a fused polynuclear compound represented by the following formula : 1In the above formula, X1, X2 and X3 may preferably oxygen atom or C2. This improvement also reduces the switching level uncertainty due to manufacturing process variations by adding compensation devices to a first inverter stage in the input buffering stage so as to increase noise margin. The standard voltage setter detects each of a plurality of common pulse signal sections of the standard signal in accordance with its signal-wave characteristic, and transmits each value of the plurality of standard voltage sections to a corresponding laser driver in accordance with a detected common pulse signal section. The reinforcing rod has ribs with different geometric andor material properties.